A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained physical activity. What sample size should be obtained the wishes the estimate to be within three percentage points
with 90% confidence, assuming that
(a) he uses the estimates of 21.3% male and 19.5% female from a previous year?
(b) he does not use any prior estimates?
(a)n (Round up to the nearest whole number)
(b) (Round up to the nearest whole number.)

Answers

Answer 1

Using the z-distribution and the formula for the margin of error, it is found that:

a) A sample size of 54 is needed.

b) A sample size of 752 is needed.

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which z is the z-score that has a p-value of [tex]\frac{1+\alpha}{2}[/tex].

The margin of error is of:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

90% confidence level, hence[tex]\alpha = 0.9[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.9}{2} = 0.95[/tex], so [tex]z = 1.645[/tex].

Item a:

The estimate is [tex]\pi = 0.213 - 0.195 = 0.018[/tex].

The sample size is n for which M = 0.03, hence:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.645\sqrt{\frac{0.018(0.982)}{n}}[/tex]

[tex]0.03\sqrt{n} = 1.645\sqrt{0.018(0.982)}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.018(0.982)}}{0.03}[/tex]

[tex](\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.018(0.982)}}{0.03}\right)^2[/tex]

[tex]n = 53.1[/tex]

Rounding up, a sample size of 54 is needed.

Item b:

No prior estimate, hence [tex]\pi = 0.05[/tex]

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.645\sqrt{\frac{0.5(0.5)}{n}}[/tex]

[tex]0.03\sqrt{n} = 1.645\sqrt{0.5(0.5)}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.5(0.5)}}{0.03}[/tex]

[tex](\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.5(0.5)}}{0.03}\right)^2[/tex]

[tex]n = 751.7[/tex]

Rounding up, a sample of 752 should be taken.

A similar problem is given at https://brainly.com/question/25694087


Related Questions

plzz help don't understand

Answers

Answer:

3b

Step-by-step explanation:

[tex]3\sqrt{b^{2} }[/tex]

= 3b


The total amount of snowfall last ski season was 50 inches. This season, the total amount was 56 inches. The
percent of snowfall this year is what compared to last year?

Answers

Answer:

12% increase compared to last years

Step-by-step explanation:

a) 15 - 4 X 6 + 30 - 5​

Answers

Answer:

16

Step-by-step explanation:

15 – 24 +30 – 5

–9+25

= 16

Answer:

16

Step-by-step explanation:

(Remember to always use order of operations or "PEMDAS")

First do 4 × 6 = 24, then subtract 24 from the 15 to get -9. Now add -9 to 30 to get 21. Finally, subtract 5 from 21 to get 16.

Hope this helps you :)


Given that angle a = 54° and angle b = 48°, work out 3.
a
b
х
The diagram is not drawn accurately.
х

Answers

9514 1404 393

Answer:

  x = 78°

Step-by-step explanation:

The sum of the interior angles of a triangle is 180°.

  x + a + b = 180°

  x = 180° -a -b . . . . . . . . add -a-b to both sides

  x = 180° -54° -48°

  x = 78°

Please give me examples to use

Answers

Answer:

cy+d to the middle of the problem

HELP ME OUT PLEASE

A die was rolled six times. The polls were 1,2,3,3,4 and 5. What is the mean deviation for this data!

A) 3/5

B) 1

C) 2

D) 6​

Answers

Answer:The mean deviation of the given data is;

Option B: 1

Step-by-step explanation:

Σ(x - x¯)/n

Now, x¯ is the mean = (1 + 2 + 3 + 3 + 4 + 5)/5

x¯ = 3

Thus;

1 - 3 = -2

2 - 3 = -1

3 - 3 = 0

3 - 3 = 0

4 - 3 = 1

5 - 3 = 2

Mean deviation is usually a positive value. Thus;

Σ(x - x¯) = 2 + 1 + 0 + 0 + 1 + 2

Σ(x - x¯) = 6

Thus;

Σ(x - x¯)/n = 6/6

Σ(x - x¯)/n = 1

Analyze the table below and complete the instructions that follow.


Blue
Brown
Green
Total
Male
10
B
1
28
Female
D
15
C
26
Total
18
A
4
E

Solve for the variables in the table.

Answers

Answer:

C

Step-by-step explanation:

Evaluate the expression( 3x2)2

Answers

Answer:

12

Step-by-step explanation:

Its 12 because you would do what’s in the parentheses first, which is 3x2 which is 6, then multiply it by 2. 6x2=12.

Round your answer to the Nearest tenth

Answers

v = (8x7) / 17
v = 56 / 17
v = 3.294
v = 3.3

Answer:

3.3 or [tex]\frac{56}{17}[/tex]

Step-by-step explanation:

v/7 = 8/17                    

Cross multiply ... v times 17 & 7 times 8

17v = 56

Divide both sides by 17

v = 56/17

Keep your answer as a fraction OR

Convert to a decimal : 3.3

Explain how you could solve the following using equal groups.

Linda wants to bake 48 cookies. The cookie tray has room for 8 cookies. How many batches will she have to bake to make 48 cookies?

Answers

Answer:

6

Step-by-step explanation:

48/8=6

You invest AED 5000 in a saving account that earns 4% interest each year. If you do not use the account for a year, how much money will you have in your account after a year?

Answers

Answer:

5200 AED or 1404 USD

Step-by-step explanation:

You have 5000 in your account. If your money grows 4% each year, it's basically like multiplying by 1.04.

5000 * 1.04 = 5200

If the question is asking in USD, the conversion rate from AED to USD is

AED * 0.27 = USD

We can substitute

5200 AED* 0.27 = 1404 USD.

HELP ME OUT PLEASE!!!​

Answers

Answer:

I think it is the second one.

Step-by-step explanation:

It might be right.

Hope this helps! :)

What is the length of CD, given that figure ABCD is a rectangle?
B
13
С
10
A
D
O A. 26
O B. 10
O C. 13
O D. 20

Answers

Answer:

It'll be B.10

Step-by-step explanation:

Rectangles always have 2 side lower than the other2 . BC and AD are same length so they are both 13. BA and CB are the same length to It has to be 10.

Hope this helps :)

The answer would be B. 10

What's the walker instructions for this problem?​

Answers

I'm not sure what the stuff in blue indicates. If we ignore that, then the flat horizontal line means the person stays motionless at some distance away from the motion detector. They don't move because the slope = rise/run is zero here, to indicate a zero speed.

what is the answer to this question (LAST QUESTION)

Answers

Answer:

Same thing as before

Convert into improper for it to be easier to solve

11/3 - 9/5

THe common multiple is 15 here

55/15 - 27/15 = 28/15

Now 28/15 into a mixed is

1 13/15

Write the equation of a parabola that has a vertex of (-2,5.5) and passes through the point (-2.5,2.5).

Answers

The equation of a parabola that has a vertex of (-2, 5.5) and passes through the point (-2.5, 2.5) is  [tex]y=-12(x+2)^2+5.5[/tex]

The vertex form of the equation of a parabola is:

[tex]y=a(x-h)^2+k[/tex]

where (h, k) is the vertex of the parabola

(x, y) is the point that the parabola passes through

The vertex, (h, k) = (-2, 5.5)

The point, (x, y) = (-2.5, 2.5)

Substitute h = -2, k = 5.5, x = -2.5, and y = 2.5 into the equation to solve for a.

[tex]2.5=a(-2.5-(-2))^2+5.5\\\\2.5=a(-2.5+2)^2+5.5\\\\2.5-5.5=a(-2.5+2)^2\\\\-3=a(-0.5)^2\\\\-3=0.25a\\\\a = \frac{-3}{0.25} \\\\a = -12[/tex]

Therefore, the equation of the parabola is:

[tex]y=-12(x-(-2))^2+5.5\\\\y=-12(x+2)^2+5.5[/tex]

Learn more here: https://brainly.com/question/25667732

Express 405 1/3 in simplest radical form.

Answers

Answer:

3 cube root of 15

Step-by-step explanation:

theres your simple radical form

8(152/3) is 405 1/3 in simplest radical form.

What is simplification?

Simplifying procedures is one way to achieve uniformity in job efforts, expenses, and time. It reduces diversity and variation that is pointless, harmful, or unneeded. Parenthesis, exponents, multiplication, division, addition, and subtraction are all referred to as PEMDAS. The order of the letters in PEMDAS informs you what to calculate first, second, third, and so on, until the computation is finished, given two or more operations in a single statement.

405 1/3 is equivalent to (405*3 + 1)/3 = 1216/3.

To express 1216/3 in simplest radical form, we can first simplify it by dividing both the numerator and denominator by their greatest common factor, which is 8.

1216/3 = (8*152)/3 = 8(152/3)

Now, we can see that 152/3 cannot be simplified any further, so the simplest radical form of 405 1/3 is: 8(152/3)

Learn more about Simplification here:

https://brainly.com/question/28996879

#SPJ2

A company has launched a Business App. for smart mobile phones, the users who installed the application in 2015 were 10000 users, and they increase by 10% each succeeding year.
a) Determine the number of users in the year 2020.
b) If the company gains on average annual revenue of OMR 12 per user, what is the total revenue gained until the end of the year 2021?

Answers

Answer: a) 15000 b) OMR 192,000

For a function to be inverse, it must be

Answers

Answer:

look at the explanation

Step-by-step explanation:

for f(x) and g(x) to be inverse,

f(g(x))=g(f(x))=x

100 POINTS If x and y are real numbers, what is the simplified radical form of [tex](x^{2} y^{5} )^{\frac{1}{5} }[/tex]

Answers

Answer: [tex]x^{2/5}[/tex][tex]y[/tex]

Step-by-step explanation:

([tex]x^{2}[/tex][tex]y^{5}[/tex])^[tex]^{1/5}[/tex]

= [tex]x^{2/5}[/tex][tex]y[/tex]

the answer will be: (x^2/5) y
(x to the power of 2/5, times y)

What is the equation of the line in slop-intercept form?



Enter your answer in the blank spots




y= __x + __

Answers

y = 5/2x + 5
or
y = 2.5x + 5

Answer:y=2.5x+5 i thank

Step-by-step explanation:

The difference of a number and six is negative four

Answers

10, i believe. i hope this helps :)

grahm's birthday Is on 26th May which day of the week Is his birthday? ​

Answers

Answer:

Wednesday, 2021,Thursday, 2022

Simplify the following expression.

(33x + 53y) + (44x - 20y)
A.
86x + 33y
B.
77x + 73y
C.
77x + 33y
D.
86x + 73y

Answers

Answer:

77x+33y

Step-by-step explanation:

Eliminate redundant parentheses

(33x+53y)+(44x−20y)

33+53+44−20

Combine like terms

33x+53y+44x−20y

77+53−20

Combine like terms

77x+53y−20y

77+33

Solution:

77+33

Answer: The answer would be D.

Step-by-step explanation:

All you have to do is combine like terms.

Pretend that the parenthesis aren't there. 13x + 9y + 38x + 33y.

When you combine like terms, you add or subtract the terms that have the same variable attached.

13x + 38x = 51x.

9y + 33y = 42y

51x + 42y.

I hope I helped.

Brainliest would be appreciated.

Assume that x is a positive acute angle.
Given: sin x =28/53
Find: sin 2x

Answers

Answer:

its sophisticated but answer is 3

Step-by-step explanation:

you have to dive deep into it and research

Make g the subject of the formula r = 4g +7​

Answers

Answer:

4 better explanation inbox

Step-by-step explanation:

Materials and labor for each pet groomed
costs $15. The business also has fixed costs
of $1,000 each month. Define a cost
function for this business.

Answers

Answer:

f(x) = 15x + 1,000

Step-by-step explanation:

y = mx + b

the 15 is the slope or rate and 1000 is the fixed value ( y intercept)

The first factor has a degree of
2
.
The second factor has a degree of
3
.
The third factor has a degree of
.
The product has a degree of
.

Answers

Answer:

first = 2,second= 3

Step-by-step explanation:

F*s= 2*3

= 6

Two hundred students are going to dine with the principal as their reward for perfect attendance. A random survey of 25 of these students was
conducted to determine how many of each meal should be prepared for dinner. The results are shown below.
• 12 students like pizza
8 students like cheeseburger
. 5 students like taco
Based on the survey results, which of these is the best prediction of the meals liked by the 200 students. (1.6H)
O A There are 16 students who want a cheeseburger.
OB There are 52 students who want either a cheeseburger or a taco.
O C There are 24 more students who want a taco than want a cheeseburger.
OD There are 32 more students who want pizza than want a cheeseburger.

Answers

DThere are 32 more students who want pizza than want a cheeseburger.

BRAINLIEST?

(5.8 times 10^-15) - (4.4 times 10^-14)

Answers

Answer:

−3.82×10^-14

Step-by-step explanation:

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the  

10. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

−3.82×10^-14

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