3. P343. 13. A sociologist is interested in surveying workers in computer-related jobs to estimate the proportion of such workers who has changed jobs within the past years. (a) In the absence of preliminary data, how large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05? (b) In a sample of 100 workers, 20 of them had changed jobs within the past year. Find a 95% confidence interval for the proportion of workers who have changed jobs within the past year. (c) Based on the data in part (b), estimate the sample size needed so that the 95% confidence interval will specify the proportion to within ±0.05.

Answers

Answer 1

Answer:

a) A sample of 385 must be taken.

b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

c) A sample of 246 is needed.

Step-by-step explanation:

Question a:

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]1-\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 zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

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

Absence of preliminary data:

This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?

A sample of n must be taken.

n is found when [tex]M = 0.05[/tex]. So

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

[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96*0.5[/tex]

Dividing both sides by 0.05

[tex]\sqrt{n} = 1.96*10[/tex]

[tex](\sqrt{n})^2 = (19.6)^2[/tex]

[tex]n = 384.16[/tex]

Rounding up,

A sample of 385 must be taken.

Question b:

In a sample of 100 workers, 20 of them had changed jobs within the past year.

This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]

The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

Question c:

Same procedure as question a, just with [tex]\pi = 0.2[/tex]

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

[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]

[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]

[tex]n = 245.8[/tex]

Rounding up

A sample of 246 is needed.


Related Questions

What is the volume, in cubic ft, of a rectangular prism with a height of 17ft, a width of 11ftand a length of 18ft?

Answers

Answer:

i got 691ft

Step-by-step explanation:

Answer: 3366

Step-by-step explanation: (17)(11)(18)= 3366

Can someone help with number 1 please?

Answers

A
A=l x w
6/10 divided by 3/4 is 4/5

Which graph and equation shows a proportional relationship between r and y? y= 11.5% y = 1.5x - 1.5​

Answers

Answer:

y = 1.5x - 1.5​

Step-by-step explanation:

Model and Solve Equations with Geometry Concepts (7.11c) . ... Now substitute the values for x and y into the expression. 2(1. 3. )(1. 2. −3) ... 10.0+1.5 = 11.5.

HELP ASAP!!

The parent function f(x)= square root of x is translated 2 units right, compressed horizontally by a factor of 21 , and reflected across the x-axis.

Answers

Answer:

Ok? what's the question

Step-by-step explanation:

Answer:

i did my best to try and find something, do any of these help? lmk

Step-by-step explanation:

The side lengths of a triangle are 12, 19, and x units.
12
19
(The figure above gives only one possible configuration for the triangle.)
Determine the possible values of x.
Write your answer as an inequality.
Use x only once in your inequality.
D>
ISO
D20
Х
?

Answers

Answer:

7<x<31

Step-by-step explanation:

The third side of any triangle must be more than the difference between the other two sides.

x>19-12

x>7 (or) 7<x

The third side of any triangle must be less than the sum of the other two sides.

x<19+12

x<31 (or) 31>x

Put them together.

7<x<31 (or) 31>x>7

7<x<31 are the possible values of x.

What is Triangle?

A triangle is a three-sided polygon that consists of three edges and three vertices.

Given that  side lengths of a triangle are 12, 19, and x units.

We need to find the value of x.

We know that the third side of any triangle must be more than the difference between the other two sides.

x is greater than difference of nineteen and twelve

x>19-12

x>7 (or) 7<x

The third side of any triangle must be less than the sum of the other two sides.

x<19+12

x<31 (or) 31>x

From this we get the interval as

7<x<31 (or) 31>x>7

Hence, 7<x<31 are the possible values of x.

To learn more on Triangles click:

https://brainly.com/question/2773823

#SPJ2

Select the best answer for the question.
16. Phil Smith is a car salesman. Last
week his total sales amounted to
$27,650.00, and he received $1,382.50 in
commission. What is his rate of
commission?
O

Answers

Answer:

5 Percent

Step-by-step explanation:

Last week his total sales amounted to $27,650.00, and he received $1,382.50 in commission. His rate of commission is 5 percent.

daves first three test scores in algebra were 84%, 88%, and 90%. what does he need to earn on the next test so that his average for all four tests is exactly 90%?
A. 92%
B. 87%
C. 100%
D. 98%

Answers

Answer:

C gives you 90.2

Step-by-step explanation:

84+88+90+100=362

362/4=90.2

April can buy a package of 8 folders for $2.40. What is the unit price for this package?

Answers

Answer:

0.3

Step-by-step explanation:

to get the unit rate you must divided

2.40 by 8

2.40/8=0.3

Help!
This is the problem


1+10k+1-7k

Answers

Answer:

3002

Step-by-step explanation:

Very simple, just add them up.

Which of the following ordered pairs is a solution of the system of inequalities?
y > 2x2 – 8
y ≤ –x2 – 3x + 4
Question 5 options:

A)

(4, –3)

B)

(–3, –2)

C)

(5, 0)

D)

(0, –5)

Answers

9514 1404 393

Answer:

  D)  (0, -5)

Step-by-step explanation:

A graphing calculator is helpful. It shows that the point (0, -5) is in the solution spaces of both inequalities.

__

If we consider only the case of x=0, then the solution space reduces to ...

  -8 < y ≤ 4 . . . . . the constants of the two inequalities

Here, it is easy to see that y=-5 is in the solution space.

  (0, -5) is a solution

PLEASE HELP I WILL MARK YOU BRAINIEST

Answers

Answer:

The answer is (D) y < 4

Answer:

D. y < 4 im pretty sure sorry if its wrong..

Solve 4r2 – 5 = 59
{± 3}


{± 4}


{± 5}


{±6}

Answers

9514 1404 393

Answer:

  (b)  ±4

Step-by-step explanation:

  4r^2 -5 = 59 . . . . given

  4r^2 = 64 . . . . . . . add 5

  r^2 = 16 . . . . . . . . . divide by 4

  r = ±4 . . . . . . . . . . . take the square root

Rename 5/12 and 7/8 using the least common denominator

Answers

Answer:

10/24 and 21/24

Step-by-step explanation:

So the least number that both 12 and 8 will divide into is 24

so 5x2/24 and 7x3/24 so the fractions are 10/24 and 21/24

Answer:

10/24 and 21/24

Step-by-step explanation:

answers for plato test

PLEASEEEEEE HELPPPPPPPPPP MEEEEEEEEEEEEEEEE

Answers

Answer:

120.2 or in other words, the answer is the last option, D

Write the slope-intercept form of the line given point and slope. ( show work if possible please)

through: (-2,-5), slope = 5 ​

Answers

Answer:

y=5x+5

Step-by-step explanation:

y-y1=m(x-x1)

y-(-5)=5(x-(-2))

y+5=5(x+2)

y=5x+10-5

y=5x+5

VERY EASY, WILL GIVE 50 POINTS FOR CORRECT ANSWER ASAP AND WILL GIVE BRAINLIEST.

Answers

Answer:

It is D Because I'm soo Smart And the Question is easy

Larissa rolled two number cubes each with the numbers 1 through 6 larissa adds the numbers appeared on the roll which two sums have an equal chance of occurring

A. 3 and 11
B. 4 and 7
C. 5 and 8
D. 6 and 9

Answers

The answer ur looking for is (c)

Model with mathematics. Abbi has decided to
offer a 2-hour computer gaming party for her
students. She can rent the student center for $45
per hour, and she can have the technology team set
up a network for up to 10 computers for a total of
$200 for the evening. Compose function p(x) such
that x is the number of students and p(x) is the
price per student for her to break even on the cost.
Note any appropriate restrictions on the domain x.

Answers

Answer:

180,000

Step-by-step explanation:

You got to multiply all the numbers and then divide by 600 and then you het your anwser

For an F distribution, find the following:

(a) f 0.25,825
(b) f 0.10,12,15
(c) f 0.01,12,6

Answers

Answer:

1.39 ; 2.02 ; 2.90

Step-by-step explanation:

From the F - distribution calculator

F0.25, 8, 2 ;

u = 8 ; v = 25 ; cumulative probability = 1 - 0.25 = 0.75

F value = 1.39

F0.10,12,15 :

u = 12 ; v = 15 ; cumulative probability = 1 - 0.10 = 0.90

F value = 2.02

F0.01,12,6

u = 12 ; v = 6 ; cumulative probability = 1 - 0.01 = 0.90

F value = 2.90

What is the value of the exponential expression below?
36 1/2

Answers

Answer:

D. 6

Step-by-step explanation:

[tex]36 {}^{ \frac{1}{2} } = \sqrt{36} = 6[/tex]

What are the coordinates of point A

Answers

Answer:

The coordinates of point A are (-4, 3)

hope it helps

Answer:

The coordinates of point A is (-4,3)

Step-by-step explanation:

(x,y)

X= -4

Y= 3

Find the value of x.

A. 10
B. 17
C. 14
D. 7

Answers

Answer:

x = 7

Step-by-step explanation:

By a certain theorem, Congruent chords are equidistant from the center of a circle. We know these chords are congruent because the top half of the left chord and bottom half of the right chord are congruent.

We also know that a radius perpendicular to a chord will bisect it, meaning the length of each chord is 20, but that's irrelevant, really.

So, now that we know the chords are equidistant from the center, we also know that x will be equal to 7.

Have a nice day, fam.

Which expressions represent the product of a variable and a coefficient?
Choose 3 answers:
11c
1/2 t
5. 10
j. 4

Answers

Answer:

A, B, and D

Step-by-step explanation:

A variable could be represented as a letter.

Coefficient is the number multiplying a variable.

Product means multiplication.

Therefore the expressions that represent the product of a variable and a coefficient are:

11c, ½t, and j*4

If I have 2 apples and take away 1 apple, how many peanuts do I have left?

Answers

Answer:

Cannot be determined with the information given in and of itself.

Step-by-step explanation:

You would have 1 apple left. However, there is absolutely no information given about the original amount of peanuts, how many peanuts are given to you, how many peanuts are taken from you, how many apples to a peanut, etc. etc. No answer in peanuts can be given.

I would appreciate Brainliest, but no worries.

Answer:

0

Step-by-step explanation:

if you have 2 and you take one away you have 1,

you'll have 0 peanuts since apples can't become peanuts, unless you have them already or buy them; apples won't help you get peanuts.

Can somebody help me?

Answers

Answer:

1. C   2. E   3. A   4. F   5. D   6. B

Step-by-step explanation:

Answer:

a. is 3

b. is 6

c. is 1

d. is 5

e. is 2

f. is 4

Step-by-step explanation:

Please give brainliest I worked hard on this question for you.

When the circle is filled in it means greater than or equal to or less than or equal to depending on which way its going.

If its hallow it means greater than or less than, again depending on which way its going.

What is the answer for 1+4?

Answers

Answer:

man thats really hard i think youve gotta ask a professional for that

Step-by-step explanation:

Answer:

1+4=5

1-4=-3 (3)

1 x 4= 4

1/4 =4

Step-by-step explanation:

I need help again


‍♂️

Answers

Answer:

the 3rd one

Step-by-step explanation:

I NEED HELP ASAP PLEASE

Answers

It would be c.

2(4x6)= 48
2(6x10)= 120
2(4x10)= 80

48+120+80= 248!:)
it’s a just multiply

Help please!
The answer choices are -3.73, 1.58, 3.00, and 3.73

Answers

Answer:

I think its 2.73 not sure tho

Step-by-step explanation:

Answer:

I got 3.73 (I am sorry if I am wrong I haven't done it in a while but I hope this helps!)

Step-by-step explanation:

What is the quotient?

Answers

Answer:

4000000000000=4x10^12

Step-by-step explanation:

The first choice is the quotient.

Other Questions
A system that captures incoming solar radiation, stores it, and distributes it throughout a building is calledactive solar heatingphotoelectric heatingcell heatingpassive solar heating OKAY SO I NEED HELP BC I HAVE TO GO TO THE GYM BUT THIS IS DUE BEFORE I GET BACK What is the surface area of this right rectangular prism glass slab with dimensions of 20 inches by 3 inches by 12 inches?a.576b.588c.672d.648 Equation of the line pls help Sams kids talked him into putting up the basketball hoop that their grandparents got them for Christmas. On a quiet Saturday afternoon, Sam is busy nailing the backboard to the front of their garage facing the street when one of the officers of the homeowners association walks by. "Im so sorry," she says, "but youll have to take that down. Basketball hoops in direct view of the street are prohibited." What is in place in Sams subdivision that would prohibit this? does anyone know the answer to this riddle (it's for English) 10 POINTS!!!! Some people have a lot Some people have none When you lose it...it is not very fun. You can try to build it, But It takes lots of work People with little, are sometimes called a J E R K Before clocks were invented, people told time by the sun.aIndependent ClauseDependent Clauseb Which is greats 1,200 mm or 12 m PLEASEEEEEE HELPPPPPPPPPP MEEEEEEEEEEEEEEEE What is the volume, in cubic ft, of a rectangular prism with a height of 17ft, a width of 11ftand a length of 18ft? 2 A rectangular computer screen has an area of A square inches. The width of thecomputer screen is 7 inches. Which equation represents x, the length of the computerscreen in inches?FGHJF x =G x = A + 27H x = A - 2(7)J x = Can someone please help meeeee please !!!!! Von Bora Corporation is expected pay a dividend of $1.40 per share at the end of this year and a $1.50 per share at the end of the second year. You expect Von Bora's stock price to be $25.00 at the end of two years. Von Bora's equity cost of capital is 10%. The price you would be willing to pay today for a share of Von Bora stock, if you plan to hold the stock for two years is closest to: daves first three test scores in algebra were 84%, 88%, and 90%. what does he need to earn on the next test so that his average for all four tests is exactly 90%?A. 92%B. 87%C. 100%D. 98% Man i just out da barber shop lookin all clean and then the barber says thatll be 200 dollars like - _- you must got da money like come on bring that stimy check here ya have it ik Over 400 years ago, the bark of the cinchona tree was discovered to contain a chemical compound called quinine. Quinine was, and still is, used to cure and prevent malaria. This is an early example of ____________________.a. biotechnologyb. scientific modelingc. genetic engineeringd. genomics Cardania bought a car for $12,000 ten years ago, and it has been depreciating (decreasing in value) at a rate of 8% per year since she drove it off the showroom floor.How much is the car worth today (10 years after her purchase)? Question 4 (1 point)Choose the answer.Which style of music, sometimes called the "first popular music," usually has simplelyrics about everyday life with simple instrumental accompaniment?wrapfolkO processionalO rock Model with mathematics. Abbi has decided tooffer a 2-hour computer gaming party for herstudents. She can rent the student center for $45per hour, and she can have the technology team setup a network for up to 10 computers for a total of$200 for the evening. Compose function p(x) suchthat x is the number of students and p(x) is theprice per student for her to break even on the cost.Note any appropriate restrictions on the domain x. what did Martin Luther mean when he ended the 95 Theses with the following. "Let Christians experience problems if they must and overcome them rather than live a false life based on present Catholic teaching." Steam Workshop Downloader