At a school, there are two different math classes for children of the same age. The two classes have different teachers. The school principal is interested in gauging the effectiveness of two different teaching methods and asks each teacher to try one of the methods. At the end of the semester both classes are given the same test and the results are compared.
In this experiment, what is the treatment variable?
Give an example of a variable that could confound the results.

9514 1404 393

Answer:

  acute

Step-by-step explanation:

The third angle is ...

  180° -49° -82° = 49°

So, the triangle has two angles the same, 49°. When two angle are the same, the triangle is an isosceles triangle.

The largest angle, 82°, is less than 90°, so is an acute angle. The classification acute, right, or obtuse is based on the measure of the largest angle.

The triangle is an acute isosceles triangle.

Answer:

1/2

Step-by-step explanation:

choose 2 points, I chose (-3,2) (1,4)

[tex]m = \frac{4 - 2}{1 - ( - 3)} = \frac{2}{4} = \frac{1}{2} [/tex]

Answer:

3 : 7

Step-by-step explanation:

The ratio of girls to boys = 4 : 3

Since there are only two possible genders :

Then the total fraction of student is the sum of the ratio = (4 + 3)

Since,

Boys = 3

The ratio of boys to the total number of student in the class will be :

Boys : Total

3 : 7

Answer:

0.5000

Step-by-step explanation:

According To The Question,

The Area under the Standard Normal Curve, We Can Use the Statistical Tables , That Reported Area As P(z < a) .  

Thus, We need to use the following Relationship.

Now solve, P(z > 0) = 1 - P(z < 0) ⇔ 1 - 0.5000 ⇔ 0.5000

(Diagram, Please Find in Attachment)

Answer:

Step-by-step explanation:

[tex]10C_{7}\times (0.2)^{7} \times (0.8)^{3}\\[/tex]

The probability that a student guesses the correct answer to exactly 7 questions is 0.004.

The probability of exactly x successes on n repeated trials in an experiment which has two possible outcomes is called binomial probability.

[tex]P_{x} =nC_{x} P^{x} q^{n-x}[/tex]

where,

P is binomial probability

x is number of times for a specific outcome within n trials

[tex]nC_{x}[/tex] number of combinations

p is probability of success on a single trial

q is probability of failure on a single trial

n is number of trials

According to the given question.

A test consisted of 10 multiple choices.

⇒ Number of trials,  n = 10

The student have to give exactly 7 correct answers.

⇒ x = 7

The probability of being correct in one trial, p = [tex]\frac{1}{5}[/tex]    

(only one option is correct among fives)

So, the probability of being incorrect/wrong in one trial, q = [tex]1-\frac{1}{5} =\frac{4}{5}[/tex]

Therefore, the probability that a student guesses the correct answer to exactly 7 questions is given by

[tex]P_{x} = 10C_{7} (\frac{1}{5}) ^{7} (\frac{4}{5} )^{3}[/tex]

⇒ [tex]P_{x} = \frac{10!}{7!3!} (0.2)^{7}( 0.8)^{3}[/tex]

⇒[tex]P_{x} = 120(0.0000128)(0.512)[/tex]

⇒ [tex]P_{x} =0.004[/tex]

Hence, the probability that a student guesses the correct answer to exactly 7 questions is 0.004.

Find out more information about binomial probability here:

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Answer:

7/√2 cm

Step-by-step explanation:

Area of circle = 77 cm^2

=> π(r)^2 = 77

=> (22/7) x (r)^2 = 77

=> (r)^2 = (77 x 7) / 22

=> (r)^2 = 49/2

=> (r) = 7/√2 cm

Answer:

I think you are missing something unless the answer is a horizontal line.

Step-by-step explanation:

Answer:

square root

Step-by-step explanation:

just took the test :)

Answer:

The contrapositive of the statement is true.

Step-by-step explanation:

For a general statement:

p ⇒ q

The contrapositive statement is:

¬q ⇒ ¬p

where:

¬q is the negation of the proposition q.

Here we have the statement:

If two angles are not complements, then their measures do not add up to 180°

So we have:

p = two angles are not complements

q = their measures do not add up to 180°

Then the negations are:

¬p = two angles are complements

¬q = their measures do add up to 180°

The contrapositive statement is:

"if for two angles their measures do add up to 180°, then the two angles are complements"

This is true, if for two angles the sum of their measures is equal to 180°, then these angles are complementary.

Then: The contrapositive of the statement is true.

Answer:

bad gvkvkgcnhvvjzadhljang

v

gjddkfzutwdjtabkf

Answer:

Mean = 4.8875

Median = 4.6

Mode = 4.5 and 7.7

Step-by-step explanation:

Mean is the sum of total of data divided by the sample size

Sum total = 1.5 + 4.7 + 6 + 7.7 + 7.7 + 4.5 + 2.5 + 4.5

Sum total = 39.1

Sample size = 8

Mean = 39.1/8

Mean = 4.8875

To get the median we need to first rearrange

1.5, 2.5, 4.5, 4.5, 4.7, 6, 7.7, 7.7

Median = 4.5 + 4.7/2

Median = 4.6

Hence the median is 4.6

Mode is the value occuring the most. Since 4.5 and 7.7 both occurs twice, hence the mode of the data is 4.5 and 7.7

Answer:

8x + 2y + 250 grams

Step-by-step explanation:

The box contains

8 text   books each with a mass of x grams = 8x

2 dictionaries each with a mass of  y grams = 2y

1 box                                                                 = 250 grams

Total                                                                 = 8x + 2y + 250

Answer:

Correct answers= 18

Incorrect answers=30-18= 12 answers

Step-by-step explanation:

total questions=30

correct answers= x

incorrect answers= 30-x

given: 5 marks for each correct answer

therefore, marks for correct answers = 5*x = 5x

Given: 1 mark deducted for every incorrect answer

therefore, marks deducted = 1(30-x) = 30-x

Total marks scored= 78

★  The Difference of Marks scored for Correct Answers and Marks deducted for Incorrect Answers should be equal to 78

5x- (30-x) =78

5x-30+x=78

5x+x=78+30

6x= 108

x=108/6 = 18

Correct answers= 18

Incorrect answers=30-18= 12 answers

Answer:

120°

Step-by-step explanation:

m L SPU = 180° - 60° = 120°

Answer:

8

Step-by-step explanation:

40÷5=8

Hope this helps! :)

Step-by-step explanation:

[tex] \sqrt{53} [/tex]

Answer:

0.0296 = 2.96% probability that at least one bit is received incorrectly.

Step-by-step explanation:

For each bit, there are only two possible outcomes. Either it is received correctly, or it its not. Each bit is received independently of the others, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

The probability of each bit being received incorrectly is 0.001

This means that [tex]p = 0.001[/tex]

30-bit message

This means that [tex]n = 30[/tex]

What is the probability that at least one bit is received incorrectly?

This is:

[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{30,0}.(0.001)^{0}.(0.999)^{30} = 0.9704[/tex]

Then

[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0.9704 = 0.0296[/tex]

0.0296 = 2.96% probability that at least one bit is received incorrectly.

Answer:

=>The graph of an exponential relation is also non-linear.

=>The graph of an exponential relation becomes nearly parallel to x-axis on one and then curves upward and becomes nearly parallel to the y-axis on the other sid.

The average rate of change from 0 to 2 of the function represented by the graph is  [tex]\frac{3}{2}[/tex].

It is a measure of how much the function changed per unit, on average, over that interval. It is derived from the slope of the straight line connecting the interval's endpoints on the function's graph.

According to the question

[tex]x_{1} =0[/tex], [tex]x_{2} =2[/tex]

f(0) = 1, f(2) = 4

The average rate of change = [tex]\frac{f(x_{2})-f(x_{1}) }{x_{2}-x_{1} }[/tex]

= [tex]\frac{f(2)-f(0) }{2-0 }[/tex]

= [tex]\frac{4-1}{2}[/tex]

= [tex]\frac{3}{2}[/tex]

Hence, the average rate of change from 0 to 2 of the function represented by the graph is  [tex]\frac{3}{2}[/tex].

Find out more information about average rate of change here

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Answer:

The standard error for the new sample size will be of 33.75.

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Standard error as 67.5 for samples of a particular size.

We have that [tex]s = \frac{\sigma}{\sqrt{n}}[/tex], that is, the standard error is inversely proportional to the square root of the sample size, so if you quadruple (4x) the sample size, the standard error will be divided by half. So

67.5/2 = 33.75

The standard error for the new sample size will be of 33.75.

The question is incomplete. The complete question is :

The population of a certain town was 10,000 in 1990. The rate of change of a population, measured in hundreds of people per year, is modeled by P prime of t equals two-hundred times e to the 0.02t power, where t is measured in years since 1990. Discuss the meaning of the integral from zero to twenty of P prime of t, d t. Calculate the change in population between 1995 and 2000. Do we have enough information to calculate the population in 2020? If so, what is the population in 2020?

Solution :

According to the question,

The rate of change of population is given as :

[tex]$\frac{dP(t)}{dt}=200e^{0.02t}$[/tex]  in 1990.

Now integrating,

[tex]$\int_0^{20}\frac{dP(t)}{dt}dt=\int_0^{20}200e^{0.02t} \ dt$[/tex]

                    [tex]$=\frac{200}{0.02}\left[e^{0.02(20)}-1\right]$[/tex]

                   [tex]$=10,000[e^{0.4}-1]$[/tex]

                    [tex]$=10,000[0.49]$[/tex]

                    =4900

[tex]$\frac{dP(t)}{dt}=200e^{0.02t}$[/tex]

[tex]$\int1.dP(t)=200e^{0.02t}dt$[/tex]

[tex]$P=\frac{200}{0.02}e^{0.02t}$[/tex]

[tex]$P=10,000e^{0.02t}$[/tex]

[tex]$P=P_0e^{kt}$[/tex]

This is initial population.

k is change in population.

So in 1995,

[tex]$P=P_0e^{kt}$[/tex]

   [tex]$=10,000e^{0.02(5)}$[/tex]

   [tex]$=11051$[/tex]

In 2000,

[tex]$P=10,000e^{0.02(10)}$[/tex]

   [tex]=12,214[/tex]

Therefore, the change in the population between 1995 and 2000 = 1,163.

Answer:

Six at top, ten at second, twenty-seven at third, and four at bottom.

Answer:

lleva 10 000 tornillos un contenedor

Step-by-step explanation:

Answer:

-21

Step-by-step explanation:

4(x+9) = 4x+36

4x+36 = 2x-6

    -36        -36

minus 36 from both sides

4x = 2x-42

2x = -42

-42/2 = -21

x = -21

Hi there!

We are given the equation below:

[tex] \large \boxed{4(x + 9) = 2x - 6}[/tex]

1. Expand 4 in the expression.

[tex] \large{(4 \times x) + (9 \times 4) = 2x - 6} \\ \large{(4x) + (36) = 2x - 6}[/tex]

Cancel the brackets.

[tex] \large{4x + 36 = 2x - 6}[/tex]

2. Isolate x-term and solve for the variable.

[tex] \large{4x - 2x = - 6 - 36}[/tex]

Finally, combine like terms.

[tex] \large{2x = - 42}[/tex]

Then divide both sides by 2 so we can finally leave only x-term.

[tex] \large{ \frac{2x}{2} = \frac{ - 42}{2} } \\ \large \boxed{x = - 21}[/tex]

3. Check the solution if it is right or wrong.

To check the answer, we simply substitute the value of x which is -21 in the equation and see if both sides are equal or not. If both sides are equal then the answer is correct, if not then the answer is wrong. Therefore,

[tex] \large{4(x + 9) = 2x - 6 \longrightarrow 4( - 21 + 9) = 2 ( - 21) - 6} \\ \large{4( - 12) = - 42 - 6} \\ \large{ - 48 = - 48}[/tex]

Since both sides are equal when substitute in x = -21.

4. Answer

I hope this helps and let me know if you have any doubts!

Hi there!  

»»————-　★　————-««

I believe your answer is:  

"Line y = −2x + 3 intersects line y = x − 5."  

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

See the Graph Attached

⸻⸻⸻⸻

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.  

Answer:

Equation: [tex](x-2)^2=16(y-2)[/tex]

Vertex: [tex](2,2)[/tex]

Directrix: [tex]y=-2[/tex]

Focus: [tex](2,6)[/tex]

Step-by-step explanation:

Standard Form of Vertical Parabola:

We know that our vertex is [tex](h,k)[/tex] -> [tex](2,2)[/tex], therefore, we can determine the value of [tex]p[/tex] by selecting a point from the parabola as [tex](x,y)[/tex]:

[tex](x-h)^2=4p(y-k)[/tex]

[tex](x-2)^2=4p(y-2)[/tex]

[tex](6-2)^2=4p(3-2)[/tex]

[tex](4)^2=4p(1)[/tex]

[tex]16=4p[/tex]

[tex]4=p[/tex]

Therefore:

Conclusion:

Review the graph for a visual

Answer:

The amswer is 48.

Step-by-step explanation:

120×0.40=48

Answer:

[tex]x_1 = -t[/tex]

[tex]x_2 = s[/tex]

[tex]x_3 = 0[/tex]

[tex]x_4 = t[/tex]

Step-by-step explanation:

Given

[tex]\left[\begin{array}{cccc}1&0&0&1\\0&0&1&0\\0&0&0&0\end{array}\right][/tex]

Required

Determine x1 to x4

First, we write the augmented matrix

[tex]\left[\begin{array}{cccc}1&0&0&1\\0&0&1&0\\0&0&0&0\end{array}\right] = \left[\begin{array}{c}0&0&0\end{array}\right][/tex]

Taking the position of each column, we have:

[tex]x_1 + 0 + 0 +x_4 = 0[/tex]

[tex]0 + 0 + x_3 +0 = 0[/tex]

[tex]0 + 0 + 0 + 0 = 0[/tex]

There is no explicit equation for [tex]x_2[/tex]

So: [tex]x_2 = s[/tex] ----- arbitrary variable

[tex]x_1 + 0 + 0 +x_4 = 0[/tex] implies that:

[tex]x_1 + x_4 = 0[/tex]

[tex]0 + 0 + x_3 +0 = 0[/tex] implies that

[tex]x_3 = 0[/tex]

[tex]0 + 0 + 0 + 0 = 0[/tex] implies that

[tex]0 = 0[/tex]

So, we have:

[tex]x_1 + x_4 = 0[/tex]

[tex]x_3 = 0[/tex]

[tex]x_1 + x_4 = 0[/tex] becomes

[tex]x_1 = -x_4[/tex]

Let

[tex]x_4 = t[/tex]

So:

[tex]x_1 = -x_4[/tex]

[tex]x_1 = -t[/tex]

Where t , s are real numbers

Answer:

Step-by-step explanation:

The natural logarithm of x is generally written as ln x, loge x, or sometimes, if the base e is implicit, simply log x.

Answer:

Ln x as opposed to log x

Step-by-step explanation:

Answer:

1. A. Quantitative data

B. Quantitative data

C. Qualitative data

D. Quantitative data

E. Qualitative data

F. Quantitative data

2.a. Yearly salaries: interval or ratio data

b. Employee numbers: interval or ratio data

c. Area codes : nominal data

d. The ages: interval or ratio data

e. Survey answers: ordinal data

f. IQ index: interval or ratio data

Explanation:

Qualitative data is data in the form of a quality such as a characteristic. It is usually a noun, such as whether a person is fair or dark in complexion. Quantitative data is data in form of quantity such as the amount in dollars of one's salary.

There are four levels of data measurement. They are: nominal data, ordinal data, interval data, and ratio data. Nominal and ordinal data are qualitative data while interval and ratio data are quantitative data.

Answer:

3:6:9

Step-by-step explanation:

1/1+2+3 × 90 = 15

2/1+2+3 × 90 = 30

3/1+2+3 × 90 = 45