I need help with this:
A floor is made up of 50 triangular tiles , the sides of each triangle being 9 cm, 28 cm and 35 cm. Calculate a rough estimate for polishing the tiles at the rate of 75 paise per cm2. Using herons formula

Answers

Answer 1

The amount for polishing the triangular tiles at rate of 75 paise cm² is 3306 rupees.

Given data ,

To calculate the area of each triangular tile, we can use Heron's formula, which is based on the lengths of the triangle's sides.

Heron's formula states that for a triangle with side lengths a, b, and c, the area (A) can be calculated as:

A = √(s(s - a)(s - b)(s - c))

where s is the semi perimeter of the triangle given by:

s = (a + b + c) / 2

In this case, the sides of each triangular tile are 9 cm, 28 cm, and 35 cm.

Calculating the semi perimeter:

s = (9 + 28 + 35) / 2

s = 72 / 2

s = 36 cm

Calculating the area using Heron's formula:

A = √(36(36 - 9)(36 - 28)(36 - 35))

A = √(36 * 27 * 8 * 1)

A = √(7776)

A ≈ 88.18 cm²

Since there are 50 triangular tiles, the total area of the floor is approximately ,

50 x 88.18 = 4409 cm².

To calculate the cost of polishing the tiles at a rate of 75 paise (0.75 rupees) per cm², we multiply the total area by the rate:

Cost = 4408 cm² x 0.75 rupees/cm²

Cost ≈ 3306 rupees

Hence , the rough estimate for polishing the tiles would be 3306 rupees

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Related Questions

The table to the right shows the total medal counts for some countries at the close of the 2016 Rio de Janeiro Olympics. Use the table to find the percentile rank of each of the following countries. A. Brazil: Olympic Medal Counts Country Total Medals Australia 29 Brazil 19 Canada 22 China 70 France 42 Great Britain 67 Japan 41 New Zealand 18 Russia 56 United States 121 B. Japan: C. Russia: D. China:

Answers

A. Brazil is in the 30th percentile in terms of Olympic medal count in this dataset.

B. Japan is in the 40th percentile in terms of Olympic medal count in this dataset.

C. Russia is in the 50th percentile in terms of Olympic medal count in this dataset.

D. China is in the 90th percentile in terms of Olympic medal count in this dataset.

A. To find the percentile rank of Brazil, we need to first determine the total number of countries in the dataset. In this case, there are 10 countries.

Next, we need to determine how many countries Brazil outperformed in terms of medal count. Looking at the table, we can see that Brazil has more medals than 3 countries (Australia, New Zealand, and Brazil itself) and less than 6 countries (Canada, China, France, Great Britain, Japan, and the United States).

Therefore, the percentile rank of Brazil can be calculated as follows:

Percentile rank of Brazil = (number of countries Brazil outperformed / total number of countries) x 100%

= (3 / 10) x 100%

= 30%

B. To find the percentile rank of Japan, we can follow the same approach as above.

Number of countries Japan outperformed: 4 (Australia, Brazil, Canada, and New Zealand)

Number of countries Japan was outperformed by: 5 (China, France, Great Britain, Russia, and the United States)

Percentile rank of Japan = (number of countries Japan outperformed / total number of countries) x 100%

= (4 / 10) x 100%

= 40%

C. To find the percentile rank of Russia, we can follow the same approach as above.

Number of countries Russia outperformed: 5 (Australia, Brazil, Canada, New Zealand, and Japan)

Number of countries Russia was outperformed by: 4 (China, France, Great Britain, and the United States)

Percentile rank of Russia = (number of countries Russia outperformed / total number of countries) x 100%

= (5 / 10) x 100%

= 50%

D. To find the percentile rank of China, we can follow the same approach as above.

Number of countries China outperformed: 9 (Australia, Brazil, Canada, France, Great Britain, Japan, New Zealand, Russia, and the United States)

Number of countries China was outperformed by: 0

Percentile rank of China = (number of countries China outperformed / total number of countries) x 100%

= (9 / 10) x 100%

= 90%

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To find the percentile rank of each country, we need to determine how many countries have a lower total medal count and then divide that number by the total number of countries (which is 10 in this case) and multiply by 100.

A. Brazil:
There are 9 countries with a higher total medal count than Brazil, so its percentile rank is (9/10) x 100 = 90th percentile.

B. Japan:
There are 5 countries with a lower total medal count than Japan, so its percentile rank is (5/10) x 100 = 50th percentile.

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Which question would most help you subtract: 748 – 109?

Answers

The solution of the subtraction is 639.

When subtracting 748 from 109, we notice that 748 is a much larger number than 109. This suggests that we will not be able to subtract 748 from 109 entirely, resulting in a negative answer. However, we can still proceed with finding out how many times 748 fits into 109.

To find out how many times 748 fits into 109, we perform a division operation. Divide 109 by 748, and you will get the quotient (whole number) and remainder.

109 ÷ 748 = Quotient (0) + Remainder (109)

In this case, the quotient is 0, and the remainder is 109. The quotient of 0 suggests that 748 does not fit into 109 even once without going into negative values. However, the remainder of 109 is crucial information that tells us the remaining amount after performing the subtraction operation.

Since 748 does not fit into 109 without resulting in negative numbers, we cannot find a straightforward answer to the subtraction problem. However, if we wanted to find the difference between the two numbers, we could express it as:

109 - 748 = -639

Here, the negative sign indicates that the result is negative. In this context, we can interpret the subtraction as "109 is 639 less than 748." So, while we cannot subtract 748 from 109 directly, we can determine the relative difference between the two numbers.

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3. David is a salesman for a local Ford dealership. He is paid a percent of the profit the dealership makes on each



car. If the profit is under $800, the commission is 25%. If the profit is at least $800 and less than $1,000, the



commission rate is 27.5% of the profit. If the profit is $1,000 or more, the rate is 30% of the profit. Find the



difference between the commission paid if David sells a car for a $1,000 profit and the commission paid if he



sells a car for a $799 profit?



.25x,



p(x) = 3.275x,



x < $800



$800 < x < $1000



x $1000



.30x,

Answers

David is a salesman for a local Ford dealership. He is paid a percentage of the profit the dealership makes on each car. If the profit is under $800, the commission is 25%.

If the profit is at least $800 and less than $1,000, the commission rate is 27.5% of the profit. If the profit is $1,000 or more, the rate is 30% of the profit.

Let's find the difference between the commission paid if David sells a car for a $1,000 profit and the commission paid if he sells a car for a $799 profit. We'll begin by finding the commission paid if David sells a car for a $1,000 profit.Commission paid on a $1,000 profit=.30(1,000)=300

Therefore, if David sells a car for a $1,000 profit, his commission is $300. Let's move on to finding the commission paid if he sells a car for a $799 profit. Commission paid on a $799 profit=.25(799)=199.75Therefore, if David sells a car for a $799 profit, his commission is $199.75.The difference between these commissions is:$300-$199.75=$100.25

Therefore, the difference between the commission paid if David sells a car for a $1,000 profit and the commission paid if he sells a car for a $799 profit is $100.25.

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Find the Fourier series of the given function f(x), which is assumed to have the period 21. Show the details of your work. Sketch or graph the partial sums up to that including cos 5x and sin 5x.
1. f(x) = x2 = (-1 < x < TT)

Answers

The Fourier series for f(x) is: f(x) = \frac{\pi^2}{3} + \sum_{n=1}^{\infty} \frac{2}{n^2} \cos(nx)$

The Fourier series of f(x) = x^2, where -π < x < π, can be found using the formula:

$a_0 = \frac{1}{2\pi} \int_{-\pi}^{\pi} x^2 dx = \frac{\pi^2}{3}$

$a_n = \frac{1}{\pi} \int_{-\pi}^{\pi} x^2 \cos(nx) dx = \frac{2}{n^2}$

$b_n = 0$ for all n, since f(x) is an even function

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The figure below shows a rectangular window.
68 in
36 in

Answers

Answer: If you need to find the area of the window it would be, 2,448.

Step-by-step explanation: To find the area you must multiply width times length.

a study of all the students at a small college showed a mean age of 20.5 and a standard deviation of 2.6 years. a. are these numbers statistics or parameters? explain. b. label both num

Answers

a. The mean age (20.5 years) and standard deviation (2.6 years) you provided are considered statistics.

This is because they are calculated from a sample (all the students at a small college) rather than the entire population of college students. Statistics are numerical summaries that describe the characteristics of a sample, whereas parameters describe the characteristics of an entire population.

b. To label both numbers:
- Mean age (20.5 years): This number represents the average age of students at the small college. The mean is calculated by adding all the ages and dividing by the total number of students in the sample. It is a statistic since it is based on a sample and not the entire population of college students.

- Standard deviation (2.6 years): This number indicates the degree of variation or dispersion of the ages of students in the sample. A higher standard deviation indicates a greater spread in ages, while a lower value suggests a more consistent age range. This, too, is a statistic as it is calculated from the sample rather than the entire population.

Remember, the key distinction between statistics and parameters is that statistics describe samples, while parameters describe entire populations.

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The arrival rate for a certain waiting-line system obeys a Poisson distribution with a mean of 0.5 unit per period. It is required that the probability of one or more units in the system not exceed 0.20. What is the minimum service rate that must be provided if the service duration is to be distributed exponentially?

Answers

The minimum service rate that must be provided is 1.609 units per period.

To solve this problem, we need to use the M/M/1 queueing model, where the arrival process follows a Poisson distribution, the service process follows an exponential distribution, and there is one server.

We can use Little's law to relate the average number of units in the system to the arrival rate and the average service time:

L = λ * W

where L is the average number of units in the system, λ is the arrival rate, and W is the average time spent in the system.

From the problem statement, we want to find the minimum service rate  in the system not exceeding 0.20. This means that we want to find the maximum value of W such that P(W ≥ 0.20) ≤ 0.80.

Using the M/M/1 queueing model, we know that the average time spent in the system is:

W = Wq + 1/μ

where Wq is the average time spent waiting in the queue and μ is the service rate.

Since we want to find the minimum service rate, we can assume that there is no waiting in the queue (i.e., Wq = 0).

Plugging in Wq = 0 and λ = 0.5 into Little's law, we get:

L = λ * W = λ * (1/μ)

Since we want P(W ≥ 0.20) ≤ 0.80, we can use the complementary probability:

P(W < 0.20) ≥ 0.20

Using the formula for the exponential distribution, we can calculate:

P(W < 0.20) = 1 - e^(-μ * 0.20)

Setting this expression greater than or equal to 0.20 and solving for μ, we get:

μ ≥ -ln(0.80) / 0.20 ≈ 1.609

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The scale on a map of Fort Landon is 5 inches = 95 miles. If the length on the map between Snake World and the International Space Center measures 4 inches, what is the actual distance in miles?

Answers

the actual distance between Snake World and the International Space Center is 76 miles.

To find the actual distance in miles between Snake World and the International Space Center, we need to use the given scale of the map: 5 inches = 95 miles.

If 5 inches on the map represents 95 miles, we can set up a proportion to find the actual distance in miles for the measured length on the map.

Let's denote the actual distance in miles as "x".

According to the given scale, we have the proportion:

5 inches / 95 miles = 4 inches / x miles

We can cross-multiply to solve for x:

5 inches * x miles = 4 inches * 95 miles

Simplifying further:

5x = 380

Dividing both sides by 5:

x = 380 / 5

Calculating the value:

x = 76

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s it appropriate to use a regression line to predict y-values for x-values that are not in (or close to) the range of x-values found in the data?
A. It is appropriate because the regression line models a trend, not the actual points, so although the prediction of the y-value may not be exact it will be precise. B. It is appropriate because the regression line will always be continuous, so a y value exists for every x-value on the axis. C. It is not appropriate because the correlation coefficient of the regression line may not be significant. D. It is not appropriate because the regression line models the trend of the given data, and it is not known if the trend continues beyond the range of those data.

Answers

It is important to consider the limitations of the regression line and the potential consequences of extrapolation before making any predictions outside of the range of observed data.  Option D is the correct answer.

The answer to whether it is appropriate to use a regression line to predict y-values for x-values that are not in (or close to) the range of x-values found in the data depends on the context and purpose of the analysis.

However, in general, option D, "It is not appropriate because the regression line models the trend of the given data, and it is not known if the trend continues beyond the range of those data" is the most accurate.

The regression line represents the trend observed in the given data and is not necessarily indicative of what may happen outside of that range.

Extrapolating beyond the range of data can lead to unreliable predictions, and it is better to use caution and only make predictions within the range of observed data.

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D. It is not appropriate because the regression line models the trend of the given data, and it is not known if the trend continues beyond the range of those data.

D. It is not appropriate because the regression line models the trend of the given data, and it is not known if the trend continues beyond the range of those data. The regression line is based on the values within the range of the data, and extrapolating outside of that range may not accurately reflect the trend. It is important to consider the limitations of the data and the model when using regression to make predictions.

The term "regression" was coined by Francis Galton in the 19th century to describe a biological phenomenon. The result is that the height of descendants of higher ancestors returns to the original mean (this phenomenon is also called regression to the mean).

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Bonnie deposits $70. 00 into a saving account and the account earns 4. 5% simple interest a year no money is added or taken out for 3 years how much money does Bonnie have at the end of 3 years?

Answers

We can calculate the amount of money Bonnie will have in her savings account after 3 years using the simple interest formula:

A = P(1 + rt)

where A is the total amount of money at the end of the time period, P is the initial principal or deposit, r is the annual interest rate (as a decimal), and t is the time period in years.

In this case, Bonnie deposits $70.00 into her savings account and earns 4.5% simple interest a year. We know that she does not add or take out any money for 3 years. Therefore:

P = $70.00

r = 0.045 (since the interest rate is given as a percentage, we need to divide by 100 to get the decimal form)

t = 3 years

Plugging these values into the formula, we get:

A = $70.00(1 + 0.045 x 3)

A = $70.00(1.135)

A = $79.45

Therefore, Bonnie will have $79.45 in her savings account at the end of 3 years.

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a test statistic value of 2.14 puts it in the rejection region. if the test statistic is actually 2.19 then we know the p-value is less than the significance level for the test. true or false

Answers

The statement is True.

A test statistic value of 2.14 puts it in the rejection region, which means that if the null hypothesis is true, the probability of obtaining a test statistic as extreme as 2.14 or more extreme is less than the significance level of the test. Therefore, we reject the null hypothesis at the given significance level.

If the test statistic is actually 2.19, which is more extreme than 2.14, then the probability of obtaining a test statistic as extreme as 2.19 or more extreme under the null hypothesis is even smaller than the probability corresponding to a test statistic of 2.14.

This means that the p-value for the test is even smaller than the significance level, and we reject the null hypothesis with even greater confidence.

In other words, if the test statistic is more extreme than the critical value, the p-value is smaller than the significance level, and we reject the null hypothesis at the given significance level with greater confidence.

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Plot this into a graph.
y = tan (x + 90°) - 1

Answers

The graph is attached below.

To plot the graph of the equation y = tan(x + 90°) - 1, we can follow these steps:

Determine the range of x-values you want to plot. Let's choose a range, for example, -180° to 180°.Create a table of values by substituting different x-values into the equation and calculating the corresponding y-values.

x | y = tan(x + 90°) - 1

-180° | undefined

-135° | 1

-90° | 0

-45° | -1

0° | undefined

45° | -1

90° | 0

135° | 1

180° | undefined

Note: The values are given in degrees.

Plot the points obtained from the table on a graph. The y-values correspond to the vertical axis, and the x-values correspond to the horizontal axis.Connect the points with a smooth curve to represent the graph of the equation.

Here is a graph of the equation y = tan(x + 90°) - 1 is attached.

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. prove the following proposition: if p; q 2 q with p < q, then there exists an x 2 q with p < x < q.

Answers

Let's choose c = (p + q) / 2. Since p < q, it follows that (p + q) / 2 lies between f(p) and f(q). Therefore, there exists an x between p and q such that f(x) = (p + q) / 2.

To prove the proposition "if p and q are real numbers with p < q, then there exists an x in the real numbers such that p < x < q," we can use the intermediate value theorem.

Proof:

Assume p and q are real numbers with p < q.

Consider the function f(x) = x defined on the interval [p, q]. Since f(x) is a continuous function on this interval, the intermediate value theorem guarantees that for any value c between f(p) and f(q), there exists a value x between p and q such that f(x) = c.

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let l be the line in r3 that consists of all scalar multiples of the vector w=[22−1] . find the reflection of the vector v=[293] in the line l .

Answers

The reflection of vector v=[293] in the line l that consists of all scalar multiples of the vector w=[22−1] is [-17, 192, 73].

The reflection of vector v=[293] in the line l that consists of all scalar multiples of the vector w=[22−1] is [-17, 192, 73].

To find the reflection of vector v in the line l, we need to decompose vector v into two components: one component parallel to the line l and the other component perpendicular to the line l. The component parallel to the line l is obtained by projecting v onto w, which gives us:

proj_w(v) = ((v dot w)/||w||^2) * w = (68/5) * [22,-1] = [149.6, -6.8]

The component perpendicular to the line l is obtained by subtracting the parallel component from v, which gives us:

perp_w(v) = v - proj_w(v) = [293,0,0] - [149.6, -6.8, 0] = [143.4, 6.8, 0]

The reflection of v in the line l is obtained by reversing the direction of the perpendicular component and adding it to the parallel component, which gives us:

refl_l(v) = proj_w(v) - perp_w(v) = [149.6, -6.8, 0] - [-143.4, -6.8, 0] = [-17, 192, 73]

Therefore, the reflection of vector v=[293] in the line l that consists of all scalar multiples of the vector w=[22−1] is [-17, 192, 73].

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The odds in favor of an event E occurring
are 8 to 3. Find the probability that event E
occurs.
The choices for problem number 40 from the book are given below.
a. 2.667
b. 0.375
c. 0.727
d. 0.273
e. 0.429

Answers

The probability that event E occurs, given that the odds in favor are 8 to 3, is approximately 0.727. The correct option is (c).

For the probability of event E occurring when the odds in favor are 8 to 3, we can use the formula for odds and probability conversion.

The odds in favor of event E occurring are given as 8 to 3. This means that for every 8 favorable outcomes, there are 3 unfavorable outcomes. In total, there are 8 + 3 = 11 outcomes.

To calculate the probability, we divide the number of favorable outcomes by the total number of outcomes.

The number of favorable outcomes is 8, and the total number of outcomes is 11. Therefore, the probability of event E occurring is 8/11.

Converting this to a decimal, we find that the probability is approximately 0.727.

It is important to note that odds are different from probabilities. Odds represent the ratio of favorable to unfavorable outcomes, while probabilities represent the likelihood of an event occurring on a scale from 0 to 1.



So, the probability that event E occurs is approximately 0.727, which corresponds to choice (c).

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katie wants to cover this prism in glitter if 60 of glitter is needed to cover each m square how much glitter will she need to cover the prism completely

Answers

The amount of glitter that is needed to cover the prism completely is 87.6 kg.

How to calculate the surface area of the triangular prism?

In Mathematics, the surface area of a triangular prism can be calculated by using this mathematical expression:

Total surface area of triangular prism = (Perimeter of the base × Length of the prism) + (2 × Base area)

Total surface area of triangular prism = (S₁ + S₂ + S₃)L + bh

where:

b represent the bottom edge of the base triangle.h is the height of the base triangle.L represent the length of the triangular prism.S₁, S₂, and S₃ represent the three sides (edges) of the base triangle.

By substituting the given side lengths into the formula for the surface area of a triangular prism, we have the following;

Total surface area of triangular prism = (13 × 25) + (1/2 × 21 × 10 × 2) + (16 × 25) + (21 × 25)

Total surface area of triangular prism = 325 + 210 + 400 + 525

Total surface area of triangular prism = 1,460 m².

For the amount of glitter that is needed, we have:

Amount of glitter = (60 × 1,460)/1000

Amount of glitter = 87.6 kg.

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find a cyclic subgroup of a8 that has order 4. find a noncyclic subgroup of a8 that has order 4.

Answers

A cyclic subgroup of A8 with order 4 is ⟨(1234)⟩. A noncyclic subgroup of A8 with order 4 is ⟨(12)(34), (13)(24)⟩.

To find a cyclic subgroup of A8 with order 4, we need to look for an element that generates a cyclic subgroup of order 4. One such element is (1234), which means it cyclically permutes the elements 1, 2, 3, and 4. The subgroup generated by (1234) is ⟨(1234)⟩, and its order is 4.

To find a noncyclic subgroup of A8 with order 4, we can consider elements that do not generate cyclic subgroups. One such subgroup is ⟨(12)(34), (13)(24)⟩, which consists of the permutations (12)(34) and (13)(24). This subgroup does not have a cyclic structure because neither of its generators generates a cyclic subgroup.

The order of this subgroup is also 4.

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Let X be a continuous random variable with PDF:fx(x) = 4x^3 0 <= x <=10 otherwiseIf Y = 1/X, find the PDF of Y.If Y = 1/X, find the PDF of Y.

Answers

We know that the probability density function of Y is:

f y(y) =

{-4/y^5 y > 0

{0 otherwise

To find the probability density function (PDF) of Y, we need to first find the cumulative distribution function (CDF) of Y and then differentiate it with respect to Y.

Let Y = 1/X. Solving for X, we get X = 1/Y.

Using the change of variables method, we have:

Fy(y) = P(Y <= y) = P(1/X <= y) = P(X >= 1/y) = 1 - P(X < 1/y)

Since the PDF of X is given by:

fx(x) =

{4x^3 0 <= x <=10

{0 otherwise

We have:

P(X < 1/y) = ∫[0,1/y] 4x^3 dx = [x^4]0^1/y = (1/y^4)

Therefore,

Fy(y) = 1 - (1/y^4) = (y^-4) for y > 0.

To find the PDF of Y, we differentiate the CDF with respect to Y:

f y(y) = d(F) y(y)/d y = -4y^-5 = (-4/y^5) for y > 0.

Therefore, the PDF of Y is:

f y(y) =

{-4/y^5 y > 0

{0 otherwise

This is the final answer.

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Find the slope the tangent line

Answers

The slope of the tangent line of the function f(x) = √x is 1/2√a

What is the slope to the tangent line?

To determine the slope of the tangent line of the given function, we have to find the derivative of the function and take the evaluation at that point.

Given;

f(x) = √x

Using the power rule in differentiation;

[tex]f'(x) = \frac{dy}{dx} = \frac{1}{2}x^-^\frac{1}{2}[/tex]

To determine the slope of the tangent line, let's find the evaluation of the derivative at this specific point.

Assuming;

x = a

[tex]f'(a) = \frac{1}{2}a^-^\frac{1}{2}[/tex]

This implies that the slope of the tangent line to f(x) at the specific point is ;

[tex]\frac{1}{2}\sqrt{a}[/tex]

Note that since the square root function has a non-zero slope for positive values of x, the slope of the tangent line exists for all positive values of a.

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Let X1 and X2 be jointly distributed random variables with finite variances.
a) Show that (E(X1X2))2≤E(X21)E(X22). (Hint: Note that, for any real number t, E((tX1−X2)2)≥0.)
b) Lep rho be the correlation of X1 and X2. Using the inequality of part (a), show that rho2≤1.

Answers

a) To prove the inequality (E(X1X2))2≤E(X21)E(X22), we can start by expanding the square on the left-hand side:
(E(X1X2))2 = (cov(X1,X2) + E(X1)E(X2))2
= cov(X1,X2)2 + 2cov(X1,X2)E(X1)E(X2) + (E(X1)E(X2))2
Using the fact that cov(X1,X2) = E(X1X2) - E(X1)E(X2), we can rewrite the above expression as:
E(X1X2)2 - 2E(X1X2)E(X1)E(X2) + E(X1)2E(X2)2
Now, note that for any real number t, E((tX1−X2)2)≥0. This means that the discriminant of the quadratic expression t2E(X1)2 - 2tE(X1X2) + E(X2)2 is non-positive. Therefore,
(E(X1X2))2 - E(X21)E(X22) ≤ 0
which proves the desired inequality.
b) Using part (a), we have:
rho2 = (cov(X1,X2) / (sd(X1)sd(X2)))2 ≤ 1
where sd(X1) and sd(X2) are the standard deviations of X1 and X2, respectively.
Since the standard deviations are positive, we can take the square root of both sides to obtain:
|rho| ≤ 1

Part (a) is proven by expanding the square on the left-hand side and using the fact that E((tX1−X2)2)≥0 for any real number t. Part (b) follows from part (a) and the fact that the correlation coefficient is bounded between -1 and 1.

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Roberto compró 6 cd's y 10 revistas en $ 900.00 pesos; en la misma tienda su amiga María compró 10 cd's y 4
revistas en $ 1.220.00 pesos. ¿ Cual es el sistema de ecuaciones con dos incognitas que representa el problema?

Answers

The system of linear equation that represent this problem is

6x + 10y = 900

10x + 4y = 1220

What is the system of equation?

Let's represent the number of CDs Roberto bought as x and the number of magazines as y

The problem states the following information:

Using the variables;  x and y as given;

1. Roberto bought 6 CDs and 10 magazines for $900.00 pesos. This can be represented as the equation:

  6x + 10y = 900

2. María bought 10 CDs and 4 magazines for $1,220.00 pesos. This can be represented as the equation:

  10x + 4y = 1220

So, the system of equations representing the problem is:

6x + 10y = 900

10x + 4y = 1220

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Translation: Roberto bought 6 cd's and 10 magazines for $900.00 pesos; In the same store, her friend María bought 10 CDs and 4

magazines at $1,220.00 pesos. What is the system of equations with two unknowns that represents the problem?

Find largest part when £40is shared in the ratio5:3

Answers

Answer:

£25

Step-by-step explanation:

ratio 5:3 means there are 5 + 3 = 8 parts.

40/8 = 5.

we have 5(5) + 3(5) = 25 + 15 = 40.

the largest part is  £25.

18 points here someone help me please

Answers

The average atomic mass of the element in the data table is given as follows:

28.1 amu.

How to calculate the mean of a data-set?

The mean of a data-set is given by the sum of all observations in the data-set divided by the cardinality of the data-set, which represents the number of observations in the data-set.

For the weighed mean, we calculate the mean as the sum of each observation multiplied by it's weight.

Hence the average atomic mass of the element in the data table is given as follows:

0.922297 x 27.977 + 0.046832 x 28.976 + 0.030872 x 29.974 = 28.1 amu.

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Please help me

Divide.

27 by 655 with R

Answers

Answer: 24.2

Step-by-step explanation: its right

Consider the following time series data: Observation 1 2 3 4 5 6 7 8 9 Value 10 15 18 12 20 21 21 24 26 What is the value of the 4-period centered moving average associated with period 6? Select one: a. 17.667 b. 18.500 c. 20.000 d. 17.750 e. 18.400

Answers

To calculate the 4-period centered moving average associated with period 6, we need to consider the values of the series in a window of four periods centered around period 6.

The window would include the values from periods 4, 5, 6, and 7.

Observation: 4 5 6 7

Value: 12 20 21 21

To calculate the centered moving average, we sum up the values in the window and divide by the number of periods in the window.

Average = (12 + 20 + 21 + 21) / 4 = 74 / 4 = 18.5

Therefore, the value of the 4-period centered moving average associated with period 6 is 18.5.

The correct answer is option b. 18.500

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Yt is a random walk, for t = 1,2,..., Yt = Yt−1 + et,
where et are white noises with variance σe^2. Set Y1 = e1.
(a) Showthat Yt can be rewritten asYt =et+et−1+···+e1.
(b) Find the mean function of Yt using the result in (a).
(c) Find the variance function for Yt using the result in (a).
(d) Find the autocovariance function for Yt using the result in (a).
(e) Is Yt stationary?

Answers

Yes, Yt can be rewritten as Yt = et + et-1 + ... + e1. The mean function of Yt is E(Yt) = E(et + et-1 + ... + e1) = 0. The variance function for Yt is Var(Yt) = tσe^2.

(a) Yes, Yt can be rewritten as Yt = et + et-1 + ... + e1.

We can see this by induction. For t = 1, we have Y1 = e1. Assume that the result holds for some k, i.e., Yk = ek + ek-1 + ... + e1. Then, for k+1, we have:

Yk+1 = Yk + ek+1

= ek + ek-1 + ... + e1 + ek+1

= ek + ek-1 + ... + e1 + ek+1 + 0

Thus, the result holds for all t.

(b) The mean function of Yt is E(Yt) = E(et + et-1 + ... + e1) = 0.

Since the expected value of each et is 0, the expected value of Yt is also 0.

(c) The variance function for Yt is Var(Yt) = tσe^2.

Using the result from part (a), we can write:

Yt = et + et-1 + ... + e1

Taking the variance of both sides, we get:

Var(Yt) = Var(et + et-1 + ... + e1)

= Var(et) + Var(et-1) + ... + Var(e1)

= tσe^2

(d) The autocovariance function for Yt is γ(t,s) = min(t,s)σe^2.

Using the result from part (a), we can write:

Yt = et + et-1 + ... + e1

Then, for s < t, we have:

YtYs = (et + et-1 + ... + es+1 + es)(es + es-1 + ... + e1)

Expanding the product and taking the expected value, we get:

E(YtYs) = E(etes + et-1es + ... + es+1es + es^2 + eses-1 + ... + es e1)

= E(etes) + E(et-1es) + ... + E(es+1es) + E(es^2) + E(eses-1) + ... + E(es e1)

= min(t,s)σe^2

For s > t, we can use the symmetry of the autocovariance function to get:

γ(t,s) = γ(s,t) = min(s,t)σe^2

(e) No, Yt is not stationary.

From part (b), we know that E(Yt) = 0 for all t. From part (c), we know that Var(Yt) = tσe^2, which depends on t. Therefore, Yt cannot be stationary.

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Find the radius of convergence, R, of the series. [infinity] (x − 8)n n8 + 1 n = 0 .Find the interval of convergence, I, of the series. (Enter your answer using interval notation.)

Answers

The series converges on the interval from 7 inclusive to 9 exclusive.

What is the radius of convergence, R, and the interval of convergence, I, of the series [infinity] (x − 8)n n8 + 1 n = 0 ?

To find the radius of convergence, we use the ratio test:

| (x - 8)ⁿ⁺¹ (n+9) |----------------------- = L| (x - 8)ⁿ (n+1) |L = lim{n → ∞} | (x - 8)ⁿ⁺¹ (n+9) | / | (x - 8)ⁿ (n+1) |= lim{n → ∞} |x - 8| (n+9) / (n+1)= |x - 8| lim{n → ∞} (n+9) / (n+1)= |x - 8|

So the series converges absolutely if |x - 8| < 1, and diverges if |x - 8| > 1. Therefore, the radius of convergence is R = 1.

To find the interval of convergence, we need to test the endpoints x = 7 and x = 9:

When x = 7, the series becomes:

[infinity] (-1)ⁿ (n+9) / (n+1)

n = 0

which is an alternating series that satisfies the conditions of the alternating series test. Therefore, it converges.

When x = 9, the series becomes:

[infinity] 1 / (n+1)

n = 0

which is a p-series with p = 1, which diverges.

Therefore, the interval of convergence is [7, 9).

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How are common multiples and denominators different and alike??

Answers

Common multiples and denominators are both concepts related to numbers, but they have different roles and purposes. Common multiples are used to find numbers that are multiples of two or more given numbers, while denominators specifically refer to the bottom number in a fraction.

Common multiples are numbers that are divisible by two or more given numbers. They are used to find numbers that are evenly divisible by a set of numbers. For example, the common multiples of 3 and 4 are 12, 24, 36, etc., as these numbers are divisible by both 3 and 4.

Denominators, on the other hand, are specific to fractions. In a fraction, the denominator represents the bottom number, indicating the total number of equal parts into which the whole is divided. It determines the size and proportion of each part of the fraction. For instance, in the fraction 3/5, the denominator is 5, indicating that the whole is divided into five equal parts.

While common multiples involve finding numbers divisible by given numbers, denominators are exclusively used in fractions to represent the number of equal parts in a whole. In this way, they serve different purposes. However, they are alike in the sense that they both deal with numbers and can be used in mathematical calculations and relationships.

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exercise 6.1.11: find the inverse laplace transform of 1 (s−1) 2 (s 1) .

Answers

The inverse Laplace transform of 1/((s-1)^2 (s+1)) is (1/4)e^t - (1/2)te^t + (1/4)e^(-t).

To find the inverse Laplace transform of the given function:

F(s) = 1 / ((s-1)^2 (s+1))

We can use partial fraction decomposition to break it down into simpler terms:

F(s) = A / (s-1) + B / (s-1)^2 + C / (s+1)

To solve for the coefficients A, B, and C, we can multiply both sides of the equation by the denominator and substitute in values of s to obtain a system of linear equations. After solving for A, B, and C, we get:

A = 1/4, B = -1/2, and C = 1/4

Now, we can use the inverse Laplace transform formulas to obtain the time domain function:

f(t) = (1/4)e^t - (1/2)te^t + (1/4)e^(-t)

Therefore, the inverse Laplace transform of 1/((s-1)^2 (s+1)) is (1/4)e^t - (1/2)te^t + (1/4)e^(-t).

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The inverse Laplace transform of 1/(s-1)^2(s+1) is 1/2 e^t + 1/2 t e^t - 1/4 e^-t.

The inverse Laplace transform of 1/(s-1)^2(s+1) is:

f(t) = L^-1 {1/(s-1)^2(s+1)}

Using partial fraction decomposition:

1/(s-1)^2(s+1) = A/(s-1) + B/(s-1)^2 + C/(s+1)

Multiplying both sides by (s-1)^2(s+1), we get:

1 = A(s-1)(s+1) + B(s+1) + C(s-1)^2

Substituting s=1, we get:

1 = 2B

B = 1/2

Substituting s=-1, we get:

1 = 4C

C = 1/4

Substituting B and C back into the equation, we get:

1/(s-1)^2(s+1) = 1/(2(s-1)) + 1/(2(s-1)^2) - 1/(4(s+1))

Taking the inverse Laplace transform of each term, we get:

f(t) = L^-1 {1/(2(s-1))} + L^-1 {1/(2(s-1)^2)} - L^-1 {1/(4(s+1))}

Using the Laplace transform table, we get:

f(t) = 1/2 e^t + 1/2 t e^t - 1/4 e^-t

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A seasonal index of indicates that the season is average A) o B) 0.5 C) 10 D) 100 E) 1

Answers

As seasonal index of 1 indicates that the season is average. This means that the data for the season falls in line with what is expected based on historical trends and patterns.

Seasonal indexes are used to adjust data for seasonal variations so that the underlying trends can be analyzed accurately. For example, a retailer may use seasonal indexes to adjust their sales data to account for the higher sales volume during the holiday season.

It is important to understand seasonal indexes when analyzing data and making business decisions based on seasonal trends.

A seasonal index of 0.5 would indicate that the season is weaker than average, while a seasonal index of 10 or 100 would suggest that the season is much stronger than average.

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A seasonal index is a tool used in data analysis to measure the level of seasonal variation in a given time series. An index of 1 indicates that the season is average, meaning that there is no significant deviation from the expected seasonal pattern.

A seasonal index is a numerical value that represents the relative level of a variable, such as sales or demand, during a particular season. It is usually represented as a ratio or percentage that compares the actual value of a variable to its expected value during a particular season.  An index below 1 means that the season is below average, while an index above 1 means that the season is above average.

A seasonal index of 1 (E) indicates that the season is average because it implies that the observed value during that season is equal to the overall average for all seasons. In this case, there is no significant seasonal variation or deviation from the mean.

Therefore, in the given question, the correct answer is E) 1, which means that the season is average and there is no significant deviation from the expected seasonal pattern. The use of seasonal indices is crucial in predicting future trends, identifying anomalies, and making informed decisions in various industries, such as agriculture, retail, and tourism.


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