According to the Knot, 22% of couples meet online. Assume the sampling distribution of p follows a normal distribution and answer the following questions.
a. Suppose a random sample of 150 couples is asked, "Did you meet online>" Describe the sampling distribution of p, the proportion of couples that met online.
b. What is the probability that in a random sample of 150 couples more than 25% met online?
c. What is the probability that in a random sample of 150 couples between 15% and 20% met online?
Using the normal distribution and the central limit theorem, we have that:
a) The sampling distribution is approximately normal, with mean 0.22 and standard error 0.0338.
b) There is a 0.1867 = 18.67% probability that in a random sample of 150 couples more than 25% met online.
c) There is a 0.2584 = 25.84% probability that in a random sample of 150 couples between 15% and 20% met online.
Normal Probability DistributionIn a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
It measures how many standard deviations the measure is from the mean. After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportion is approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1 - p)}{n}}[/tex], as long as [tex]np \geq 10[/tex] and [tex]n(1 - p) \geq 10[/tex].In this problem:
22% of couples meet online, hence p = 0.22.A sample of 150 couples is taken, hence n = 150.Item a:
The mean and the standard error are given by:
[tex]\mu = p = 0.22[/tex]
[tex]s = \sqrt{\frac{p(1 - p)}{n}} = \sqrt{\frac{0.22(0.78)}{150}} = 0.0338[/tex]
The sampling distribution is approximately normal, with mean 0.22 and standard error 0.0338.
Item b:
The probability is one subtracted by the p-value of Z when X = 0.25, hence:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem:
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.25 - 0.22}{0.0338}[/tex]
Z = 0.89
Z = 0.89 has a p-value of 0.8133.
1 - 0.8133 = 0.1867.
There is a 0.1867 = 18.67% probability that in a random sample of 150 couples more than 25% met online.
Item c:
The probability is the p-value of Z when X = 0.2 subtracted by the p-value of Z when X = 0.15, hence:
X = 0.2:
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.2 - 0.22}{0.0338}[/tex]
Z = -0.59
Z = -0.59 has a p-value of 0.2776.
X = 0.15:
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.15 - 0.22}{0.0338}[/tex]
Z = -2.07
Z = -2.07 has a p-value of 0.0192.
0.2776 - 0.0192 = 0.2584.
There is a 0.2584 = 25.84% probability that in a random sample of 150 couples between 15% and 20% met online.
To learn more about the normal distribution and the central limit theorem, you can check https://brainly.com/question/24663213
Use the compound interest formulas A = P1+
and A = Pert to solve.
Suppose that you have $11,000 to invest. Which investment yields the greater return over 9 years: 7.5% compounded
continuously or 7.6% compounded semiannually?
Answer:
7.5% compounded continuously yields the greatest return after 9 years
Step-by-step explanation:
Compounded interest = P(1+r/n)^(nt), where P is the principle, r is the rate of interest, n is the number of times compounded annually, and t is the time of the investment.
7.6% compounded semiannually:
I = 11000(1+0.076/2)^(2*9) --> 11000(1.038)^18 ~ $21525.09
7.5% compounded continuously:
Since it is compounded continuously, we use the mathematical constant e.
I = 11000e = $29901.01
A triangular prism and its dimensions are shown in the diagram. What is the lateral surface area of this triangular prism in square feet?
Answer:
112 ft
Step-by-step explanation:
AL = (a+b+c)h
= (6+12+10) x 4
= 112 ft
the present ages of a father and his son are 40 years and 8 years respectively how many years ago the product of their ages was 105
Answer:
5 years ago
Step-by-step explanation:
5 years ago, they were 35 years old and 3 years old. 35*3=105.
Natalie randomly answered the last three
true-or-false questions on her math quiz.
What is the probability that she got at least
two correct?
The probability that Natalie got at least two correct on the last three
true-or-false questions is 1/4.
What is the probability that Natalie got at least two correct?Probability determines the chances that an event would happen. The probability the event occurs is 1 and the probability that the event does not occur is 0.
The sample space is 2. The question is either correct or wrong.
The probability that Natalie got at least two correct = 1/2 x 1/2 = 1/4
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Write the Equation of the conic.
12. A circle with endpoints of a diameter at(1, -3) and (1,3).
Need help please thanks
Answer:
(x² -1) + y² = 9
Step-by-step explanation:
diameter=6 so radius means 6/2=3 (thus,radius²=3²=9)
centre (1 and midpoint of diameter is at y=0, so 1,0)
Help!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
53
Step-by-step explanation:
[tex] \frac{sin(56)}{78.6} = \frac{sin(90)}{ab} \\ \\ absin(56) = sin(90) \times 78.6 \\ \\ ab = \frac{sin(90) \times 78.6}{sin(56)} \\ ab = 94.8 \\ \\ {x}^{2} + {78.6}^{2} = {94.8}^{2} \\ {x}^{2} = {94.8}^{2} - {78.6}^{2} \\ {x}^{2} = 8987.04 - 6177.96 \\ {x}^{2} = 2809.08 \\ x = \sqrt{2809.08} \\ x = 53[/tex]
Help help help help
The number 1 is a common factor of _________.
A) all odd numbers
B) all even numbers
C) all whole numbers
Step-by-step explanation:
The number 1 is a common factor of C) all whole numbers
Answer:
C
Step-by-step explanation:
6 / 1 = 6. 5 / 1 = 5. every whole number is divisble by 1, even prime numbers.
If f(x)=3x−1 and f(a)=−43, what is the value of a ??
Answer:
a = -14
Step-by-step explanation:
f(a) = -43
3a - 1 = -43
3a = -43 + 1
3a = -42
a = -42/3
a = -14
Pls help me what’s the answer
Answer:
the answer is D...... ..........
Answer:
226,080 cm3
Step-by-step explanation:
The diameter of a circle is 8 miles. What is the angle measure of an arc 3 miles long?
Answer:
[tex]\sf \theta=\dfrac34 \ radians=42.97 \textdegree \ (nearest \ hundredth)[/tex]
Step-by-step explanation:
Formulae
[tex]\sf radius (r)=\dfrac12 d[/tex]
(where d is the diameter of a circle)
[tex]\sf arc \ length =r\theta[/tex]
(where r is the radius and [tex]\theta[/tex] is measured in radians)
Calculation
Given:
[tex]\sf radius (r)=\dfrac12 \cdot 8=4 \ mi[/tex]arc length = 3 miSubstituting these values into the formula for arc length:
[tex]\implies \sf 3 =4\theta[/tex]
[tex]\implies \sf \theta=\dfrac34 \ radians[/tex]
To convert radians to degrees use
[tex]\sf 1 \ rad \cdot \dfrac{180\texrdegree}{\pi}[/tex]
[tex]\implies \sf \dfrac34 \cdot \dfrac{180\texrdegree}{\pi}=42.97183463...\textdegree[/tex]
Now
[tex]\\ \rm\rightarrowtail \theta=\dfrac{l}{r}[/tex]
[tex]\\ \rm\rightarrowtail l=r\theta[/tex]
[tex]\\ \rm\rightarrowtail 3=4\theta[/tex]
[tex]\\ \rm\rightarrowtail \theta=\dfrac{3}{4}^c[/tex]
Question 7 of 11
Two angles in a triangle have measures of 13' and 65.
What is the measure of the third angle?
A 52
B. 102
C. 78
D. 143
SUBMIT
choco chip cookies cost $3.20 for the 15oz size . The 18oz size $3.75 Which is the better buy
Answer:
18 oz
Step-by-step explanation:
Choco Chip Cookies (15 oz): [tex]\frac{\$3.20}{15oz}=\frac{\$0.213}{oz}[/tex]
Choco Chip Cookies (18 oz): [tex]\frac{\$3.75}{18oz}=\frac{\$0.208}{oz}[/tex]
So, the 18oz package is the better buy by about [tex]\$0.005[/tex]
need help with geometry (number3)
Answer:
Step-by-step explanation:
If this is a parallelogram., this means that the opposite angles are congruent. Thus, the erasure of angle E is equal to the measure of angle G.
So, 10x-21=4x+27, meaning x=8.
Therefore, the measure of angle E is 10(8)-21=59 degrees
If z varies directly with the square of x and inversely with the cube of y, when x = 8, y = 2, and z = 12, what is x when y = 1 and z = 24?
PLEASE HELP!!! :))))
Step-by-step explanation:
it just means
z = k×x²/y³
12 = k×8²/2³ = k×64/8 = k×8
k = 12/8 = 3/2
24 = k×x²/1³ = 3/2 × x²/1 = 3/2 × x²
24/(3/2) = x²
48/3 = x²
16 = x²
x = 4 or
x = -4
325.39 3.26.3 326.15 326.48 from greatest to least
Answer: 1)3.26.3
2)326.15
3)325.39
4)326.48
Step-by-step explanation: you want to start from the lowest number to get your answer
The length of a rectangle is triple the width. If the area of the rectangle is 75 square inches, then find the length and width
Answer:
W = 5
L = 15
Step-by-step explanation:
Formula for Area of Rectangle is L × W
Since stated triple;
L = 3W
Area = L×W = 3W² = 75
It'll be:
3W² = 75
Divide both sides with 3:
3W² = 75
3 3
W² = 25
Then square root both sides:
w = 5
Again stated that length is triple the width:
L = 5 × 3
L = 15
Therefore;
W = 5
L = 15
Find the solution(s) to the system
y = x2-4
y = -2x – 5
Answer:
=(-1,-5)
Step-by-step explanation:
y=X1=4
y=-2x-5-2
What is the value of log625^5
Answer:
13.979
Step-by-step explanation:
log 625^5 = 5 log 625 = 5*2.79588=
Answer:
Exact Form:
1/4
Decimal Form:
0.25
Step-by-step explanation:
help plsssssssssssssssssssssssssssssssssssss
Answer:
84
Step-by-step explanation:
Find the missing numerator that will make the rational expressions equivalent.
82x+7=?6(2x+7)
The missing numerator that will make the rational expressions equivalent is (82x + 7) / (12x + 42)
What is an equation?
An equation is an expression that shows the relationship between two or more variables and numbers.
Let y represent the missing numerator, hence:
82x + 7 = y * 6(2x+7)
82x + 7 = y * (12x + 42)
y = (82x + 7) / (12x + 42)
Find out more on equation at: https://brainly.com/question/2972832
9 ft
58.5 ft
33 ft
16.5 ft
5.Find the area of the parallelogram. *
10 m
16 m
8 m
16 m
10 m
Answer:
128 because formula is bh
Step-by-step explanation:
I need help with this question
Answer:
301 feet
Step-by-step explanation:
plug in the known values
[tex]85=\sqrt{24d}[/tex]
square both sides to cancel the square root
[tex]7225=24d[/tex]
divide both sides by 24 to get d on its own
[tex]d=301.041[/tex] feet
to the nearest foot is 301 feet
Calculus hw, need help asap with steps.
Answers are in bold
S1 = 1
S2 = 0.5
S3 = 0.6667
S4 = 0.625
S5 = 0.6333
=========================================================
Explanation:
Let [tex]f(n) = \frac{(-1)^{n+1}}{n!}[/tex]
The summation given to us represents the following
[tex]\displaystyle \sum_{n=1}^{\infty} \frac{(-1)^{n+1}}{n!}=\sum_{n=1}^{\infty} f(n)\\\\\\\displaystyle \sum_{n=1}^{\infty} \frac{(-1)^{n+1}}{n!}=f(1) + f(2)+f(3)+\ldots\\\\[/tex]
There are infinitely many terms to be added.
-------------------
The partial sums only care about adding a finite amount of terms.
The partial sum [tex]S_1[/tex] is the sum of the first term and nothing else. Technically it's not really a sum because it doesn't have any other thing to add to. So we simply say [tex]S_1 = f(1) = 1[/tex]
I'm skipping the steps to compute f(1) since you already have done so.
-------------------
The second partial sum is when things get a bit more interesting.
We add the first two terms.
[tex]S_2 = f(1)+f(2)\\\\S_2 = 1+(-\frac{1}{2})\\\\S_2 = \frac{1}{2}\\\\S_2 = 0.5\\\\\\[/tex]
The scratch work for computing f(2) is shown in the diagram below.
-------------------
We do the same type of steps for the third partial sum.
[tex]S_3 = f(1)+f(2)+f(3)\\\\S_3 = 1+(-\frac{1}{2})+\frac{1}{6}\\\\S_3 = \frac{2}{3}\\\\S_3 \approx 0.6667\\\\\\[/tex]
The scratch work for computing f(3) is shown in the diagram below.
-------------------
Now add the first four terms to get the fourth partial sum.
[tex]S_4 = f(1)+f(2)+f(3)+f(4)\\\\S_4 = 1+(-\frac{1}{2})+\frac{1}{6}-\frac{1}{24}\\\\S_4 = \frac{5}{8}\\\\S_4 \approx 0.625\\\\\\[/tex]
As before, the scratch work for f(4) is shown below.
I'm sure you can notice by now, but the partial sums are recursive. Each new partial sum builds upon what is already added up so far.
This means something like [tex]S_3 = S_2 + f(3)[/tex] and [tex]S_4 = S_3 + f(4)[/tex]
In general, [tex]S_{n+1} = S_{n} + f(n+1)[/tex] so you don't have to add up all the first n terms. Simply add the last term to the previous partial sum.
-------------------
Let's use that recursive trick to find [tex]S_5[/tex]
[tex]S_5 = [f(1)+f(2)+f(3)+f(4)]+f(5)\\\\S_5 = S_4 + f(5)\\\\S_5 = \frac{5}{8} + \frac{1}{120}\\\\S_5 = \frac{19}{30}\\\\S_5 \approx 0.6333[/tex]
The scratch work for f(5) is shown below.
Expand to write an equivalent expression…
1/2(-4x + 2y)
The _____ of two sets X and Y is denoted by X-Y
Answer:
Cartesian product
Step-by-step explanation:
The Cartesian product of two sets, X and Y, denoted by X × Y, is the set of all ordered pairs (x, y), where x is an element of X and y is an element of Y: 8 (2.4.1) X × Y = { (x, y) ∣ x ∈ X ∧ y ∈ Y } For example, if Children = { Peter, Mark, Mary }, and Parents = { Paul, Jane, Mark, Mary }, then
Why would it
be better to measure the length of your classroom with
meterstick instead of a centimeter ruler?
Answer:
Meterstick
Step-by-step explanation: A standard classroom is basically just a large open room, no rooms. So it is more straight than it is curved, and if you can cover a larger area in a shorter time, it is more effecient.
If you want to be 99% confident of estimating the population mean to within a sampling error of 14 and the standard deviation is assumed to be 14, what sample size
is required?
The sample size required is
(Round up to the nearest integer.)
In
Help me solve this
View an example
Get more help
Clear all
Check answer
Answer:
16641
Step-by-step explanation:
Thank you!