In 2008 the Better Business Bureau settled 75% of complaints they received (USA Today, March 2, 2009). Suppose you have been hired by the Better Business Bureau to investigate the complaints they received this year involving new car dealers. You plan to select a sample of new car dealer complaints to estimate the proportion of complaints the Better Business Bureau is able to settle. Assume the population proportion of complaints settled for new car dealers is .75, the same as the overall proportion of complaints settled in 2008
a. Suppose you select a sample of 450 complaints involving new car dealers. Show the sampling distribution of .
b. Based upon a sample of 450 complaints, what is the probability that the sample proportion will be within .04 of the population proportion?
c. Suppose you select a sample of 200 complaints involving new car dealers. Show the sampling distribution of .
d. Based upon the smaller sample of only 200 complaints, what is the probability that the sample proportion will be within .04 of the population proportion?
e. As measured by the increase in probability, how much do you gain in precision by taking the larger sample in part (b)?

Answers

Answer 1

Answer:

Explained below.

Step-by-step explanation:

According to the Central limit theorem, if from an unknown population large samples of sizes n > 30, are selected and the sample proportion for each sample is computed then the sampling distribution of sample proportion follows a Normal distribution.

The mean of this sampling distribution of sample proportion is:

 [tex]\mu_{\hat p}= p[/tex]

The standard deviation of this sampling distribution of sample proportion is:

 [tex]\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}[/tex]

(a)

The sample selected is of size n = 450 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

[tex]\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{450}}=0.0204[/tex]

So, the sampling distribution of sample proportion is [tex]\hat p\sim N(0.75,0.0204^{2})[/tex].

(b)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

[tex]P(p-0.04<\hat p<p+0.04)=P(\frac{-0.04}{0.0204}<\frac{\hat p-p}{\sigma_{\hat p}}<\frac{0.04}{0.0204})[/tex]

                                          [tex]=P(-1.96<Z<196)\\=P(Z<1.96)-P(Z<-1.96)\\=0.975-0.025\\=0.95[/tex]

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.95.

(c)

The sample selected is of size n = 200 > 30.

Then according to the central limit theorem the sampling distribution of sample proportion is normally distributed.

The mean and standard deviation are:

[tex]\mu_{\hat p}=p=0.75\\\\\sigma_{\hat p}=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.75(1-0.75)}{200}}=0.0306[/tex]

So, the sampling distribution of sample proportion is [tex]\hat p\sim N(0.75,0.0306^{2})[/tex].

(d)

Compute the probability that the sample proportion will be within 0.04 of the population proportion as follows:

[tex]P(p-0.04<\hat p<p+0.04)=P(\frac{-0.04}{0.0306}<\frac{\hat p-p}{\sigma_{\hat p}}<\frac{0.04}{0.0306})[/tex]

                                          [tex]=P(-1.31<Z<196)\\=P(Z<1.31)-P(Z<-1.96)\\=0.9049-0.0951\\=0.8098\\\approx 0.81[/tex]

Thus, the probability that the sample proportion will be within 0.04 of the population proportion is 0.81.

(e)

The probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 450 is 0.95.

And the probability that the sample proportion will be within 0.04 of the population proportion if the sample size is 200 is 0.81.

So, there is a gain in precision on increasing the sample size.


Related Questions

Use the drop-down menu to complete the statement.
To find the quotient of 2 -
3
circle groups of
8
loo

Answers

Answer:

its 3/8

Step-by-step explanation:

Hopes this helps <3

What value of x is in the solution set of 8x -6 > 12 + 2x?
-1
0
3
5

Answers

Answer:

x:5

Step-by-step explanation:

The value of 'x' in the solution set is 5 Option D

How to determine the value of x

From the equation

8x -6 > 12 + 2x

Collect like terms

8x - 2x >  12 + 6

6 x > 18

Make 'x' subject of formula

x > 18/6

x >  3

If x is greater than 3, then x is 5

Therefore, the value of 'x' in the solution set is 5. Option D

Learn more about inequalities here:

https://brainly.com/question/24372553

#SPJ9

I know 5his is easy for yall but for me is not I need some help please I'm giving brainlist.​

Answers

Answer:

$2.99

Step-by-step explanation:

Given parameters:

Selling price = $19.95

Discount percentage  = 15%

Unknown:

Amount of discount = ?

Solution:

To find the amount of discount, ;

   Discount amount  = discount percentage x selling price

  Discount amount  = [tex]\frac{15}{100}[/tex] x 19.95

  Discount amount  = $2.99

An object is moving at a speed of 6 miles per month. Express this speed in feet per hour.

Answers

Answer:

44 ft/hr

Step-by-step explanation:

First, we convert miles to feet.

6 mi*5280 = 31680 feet

Now we convert a month to hours. For this question, lets say that a month is equal to 30 days.

30*24 hrs = 720 hrs

Now we have this speed -

31680 ft/720 hrs

Now we simplify this to -

44 ft/hr

So in conclusion, the speed of 6 miles per month is equivalent to the speed of 44 feet per hour.

CHECK PHOTO Intercepts of the graph BE SURE TO BE CORRECT PLEASE no work needed

Answers

X=(-1.2,0) and y= (0,-0.7)

Answer:

y= (0, .7)

x= (-1.2, 0)

Step-by-step explanation:

r u taking a test?

What’s the value of y in this picture

Answers

Answer: A 83

Step-by-step explanation:

Add 46 to 51 then subtract from 180 to get the correct answer(83)

A scanner can scan 20 pages and 120 seconds. How many pages can scan in 4 minutes?

Answers

Answer:

40 pages

Step-by-step explanation:

120 or 2 min x 2 = 4

20 x 2 = 40

Sorry I couldn't explain more, but I hope this helps!

Answer:

40 pages

Step-by-step explanation:

convert 4 mins -> 240 secs

then cross multiply 20/120 and x/240 (x represents the pages scanned)

u then get 120x=4800

simplify(divide)-> x=40

This table gives a few (x, y) pairs of a line in the coordinate plane. What is the x-intercept of the line?

Answers

Answer:

(22,0)

Step-by-step explanation:

22 0

35 -15

48 -30

61 -45

74 -60

Which of the following could be the ratio between the lengths of the two legs
of a 30-60-90 triangle?
Check all that apply.
OA. VE2
✓ B. 1: 13
C. 5 : 13
OD. 2.5: 6
E. 1: 2
OF. : 3

Answers

Answer:1 squad 3

2 squad 3 :6

Step-by-step explanation:

Somebody please answer this question I’m begging you

Answers

Answer: The answer is A, the y value increases by 1.5 as the x value increases by 1. Therefore A does not describe the graph.

A popular restaurant advertises that it delivers its orders within 30 minutes. Suppose the average delivery time for one store is 27 minutes with a standard deviation of three minutes. One particular order delivery has a z-score of –2.15. Which of the following statements is not a correct interpretation?

A.The delivery time was 2.15 standard deviations below the average delivery time.
B.The delivery time was less than the average delivery time by 2.15 standard deviations.
C.The delivery time was faster than the average delivery time by 2.15 standard deviations.
D.The delivery time was slower than the average delivery time by 2.15 standard deviations.

Answers

Answer: B. The delivery time was less than the average delivery time by 2.15 standard deviations.

Step-by-step explanation:

Given: A popular restaurant advertises that it delivers its orders within 30 minutes.

Suppose the average delivery time for one store is 27 minutes with a standard deviation of 3 minutes.

z-score value represents the number of standard deviations is the data value is far from mean.

Here, z-score = -2.15 which clearly indicates that the delivery time was 2.15 standard deviations below( '-' sign suggest value is below mean) the average delivery time.

Hence, the correct option is B.

Answer:

B

Step-by-step explanation:

Y-4>3 solve the question

Answers

Answer:

y>7

Step-by-step explanation:

y-4>3

+4     +4

y>7

Help me please!!..,,

Answers

Answer:

A.

Step-by-step explanation:

1.5 x 0.1 = 0.15

0.15 inches

Dont know if this is for sure right. Hope it is.

A delivery driver earns a fixed amount for each delivery she makes, and
yesterday her average hourly wage was $16.50 an hour. If she worked 6 hours
yesterday and made 11 deliveries, how much does she earn for each delivery
made?
O A. $9.90
O B. $9.00
O C. $5.50
O D. $5.00

Answers

Answer:

9 dollars or B

Step-by-step explanation:

16.50 (hourly wage) x 6 (hours worked) = 99 dollars

$99/11 deliveries= 9 dollars per delivery.

the answer your looking for is $9.00 so B hope that helps:)

How do you solve this? Without going into anything to complicated as this should be Year 10 maths

Answers

Given : ABCD is a square with each side 5cm .

To Find : The area of the shaded region .

Solution : On observing the figure we can see two quadrants , quadrant ADC & quadrant ABC .

If we join A to C , then it will be common for triangles ADC & ABC . And they will be congruent by SSS congruence condition.

Therefore the area of both quadrants will also be equal . Now we can find area of quadrant as ;

[tex]\large\boxed{\red{\bf Area_{quadrant}=\dfrac{\pi r^2}{4}}}[/tex]

Here radius will be equal to 5cm .

⇒ Area = πr² / 4 .

⇒ Area = π (5cm)² / 4 .

⇒ Area = 22/7 × 25 × 4 cm².

Area = 19.64 cm² .

So , total area of both quadrants = 39.28 cm² .

Also , area of square will be :

[tex]\large\boxed{\bf{\red{Area_{square}=(side)^2}}}[/tex]

⇒ Area = 5cm × 5cm .

Area = 25 cm².

Now , subtract area of one quadrant from the area of square = 25cm² - 19.64 cm² = 5.36 cm².

Similarly area of other white region = 5.36cm² .

And the areas sum will be = 5.36cm² × 2 = 10.72cm² .

Now , from the figure it's clear that ,

⇒ Area of unshaded region + Area of shaded region = 25cm².

⇒ 10.72cm² + ar( Shaded region ) = 25cm².

⇒ ar ( Shaded region ) = 25cm² - 10.72cm².

ar ( Shaded region ) = 14.28 cm².

Hence the area of shaded region is 14.28 cm².

[tex]\large\boxed{\red{\bf Answer = 14.28cm^2}}[/tex]

If necessary, combine like terms. (5x+1)(5x-1)

Answers

Answer:2 5x^2-1

Step-by-step explanation:

what is the place value of the 6 in 976.14

Answers

Answer:

represents the one value

Step-by-step explanation:

Ones place

Juan’s cell phone company charges $35 a month for phone service with limited data for every gigabyte of data overage the company charges $15 write an equation that represents how many gigabytes one goes over in a month if his bill was $110

Answers

Answer:15x+35=110

Step-by-step explanation:

A mug is 3/7 full. The mug contains 1/2 cup of water. Find the capacity of the mug

Answers

Answer:

7/6 cups of water is the mug's capacity

Step-by-step explanation:

Capacity refers to how much a container can contain.

Let x be the capacity of the mug.

According to the question, the mug is 3/7 full. This means that the mug contains 3/7 × x = 3x/7 of water.

It was further stated that the mug contains 1/2cup of water. This means that:

1/2 cup of water = 3x/7 of water in the mug

Hence;

1/2 = 3x/7

3x × 2 = 7 × 1

6x = 7

x = 7/6

Therefore, the capacity of that mug is 7/6 cups of water.

The capacity of the the mug if it is 3/7 full and contains 1/2 cup of water is 7/6 cup

Capacity

Given:

Quantity of the mug = 1/2 cup

let

x = full capacity of the mug

Water in the mug = 3/7 of x

= 3/7x

Note:

Water in the mug = 1/2 cup

So,

3/7x = 1/2

divide both sides by 3/7

x = 1/2 ÷ 3/7

= 1/2 × 7/3

= 7/6

Therefore, the full capacity of the mug is 7/6 cup

Learn more about fraction:

https://brainly.com/question/2929160

2. What is the measure of the missing angle? *
C-120
B-95
A-85
What is D?

Answers

Answer:

60

Step-by-step explanation:

it is because 360-(120+85+95)

Find the slope of the line y=4x+2

Answers

Answer:

M=4

Step-by-step explanation:

I hope this helps!

Please help with question plaaseeee

Answers

Answer:

Yes it is.

Step-by-step explanation:

The graph is proportional because

it is in a straight line in the graph.

Hope this helps! <3

Determine whether each equation is true or false.
-5/-1 = 5
(0/-4) = 0
-3/1 = -3
- 8/0 = 0

Answers

Step-by-step explanation:

1.False

2.True

3.True

4.False

What decimal is equivalent to StartFraction 8 over 100 EndFraction

Answers

Answer:

8/100 is equivalent to 0.08

It is 0.08 I agree with the person answer above just show evidence

ASAP!!! PLEASE HELP
10 points

Answers

This is the answer hope you get it :)

Which equation has the solution x = 9?
Select each correct answer.
+7= 8
4+ 5x = 18
81 – 3 = 6
х
2x – 3 = 15
24 – 2x = 13
3x + 2 = 25

Answers

Answer:

2x – 3 = 15

Step-by-step explanation:

2 * 9 = 18 - 3 = 15. correct

+7 = 8, no I don't really now what you mean by this...

81 - 3 = 6x? > (81 - 3 = 78) = (6 * 9 = 54), no, please tell me if I'm interpreting this right.

4 + 5x = 18 > 5 * 9 = 45 + 4 = 49, no

2 * 9 = 18, 24 - 18 = 6, no

3 * 9 = 27 + 2 = 29, no

Mr. Waxman is helping with deliveries for a shipping company. The graph shows a linear model for his delivery times on different days. (A) Identify two points on the line and write the coordinate pairs below. (B) Use your two points to find the slope, and make sure to show your work. (C) Use your slope from Part B and find the equation of the line in point-slope form. Show your work and work through the steps to transform the equation from point-slope form into slope-intercept form. (D) Based on the equation you found in Part C, predict how long it take Mr. Waxman to deliver his packages on Day 0. Approximately how much did his delivery time decrease per day? 2 SEE A

Answers

Answer:

See below

Step-by-step explanation:

Note: missing graph is attached

Solution

A) The two points are:

(4, 19) and (7, 7)

B) Slope formula: m = (y2-y1)/(x2-x1)

m = (7 - 19)/(7-4)m = -12/3m = -4

C) Point-slope formula:

y - y1 = m(x - x1)

Using one of the points we get:

y - 19 = -4(x - 4)

D) Delivery time on Day 0:

y - 19 = -4(0 - 4)y - 19 = 16y = 16 + 19y = 35 minutes

Delivery time decreases by the value of the slope which is 4 minutes per day

Ik y’all good at math, help me out yall!

Answers

Answer:

i think the answer be 150 feet per minute

hope this is right

Answer:

150

Step-by-step explanation:

use points on the line i'll use (2,300) and (1,150)

m=y2-y1/x2-x1

300-150=150

2-1=1

150/1=150

hope this helps :3

sorry if im wrong

600 students are studying in a private
school, the average monthly fee of a
student is Rs. 1200. How much amount for
tax does the school pay to the government
as education service tax at the rate of 1% in
a year? *​

Answers

Answer:

600 ×1200=720,000

720,000×12=8,640,000

8,640,000×1%=8,640,000÷100%=86,400

86,400 per year

PLZ HURRY IT'S URGENT!!!
What is the slope of the line? y=x−5
options:
undefined
1
0
-5

Answers

Answer:

1

Step-by-step explanation:

Other Questions
NASCAR driver Jimmy Johnson completed 200 laps as he crossed the finish line. From the start of the race to the finish line, is a description of his _________________.A. displacementB. speedC. velocityD. Distance What is a kind of technology used by stone age humans Which underlined phrase is a prepositional phrase?A. Test-takers were asked not to use their notes, books, or calculators.B. Before passing out the test, the teacher asked students to close their books.C. Neither of the tests this week had questions about the Pythagorean theorem.D. The teacher and the students thought that the test took longer than expected. 1.p: you pass the classq: you go to the next gradep -> ~q:_______________________________~p->~q:_______________________________ What is a likely direct effect of a community program for local residents?A. lower education costsB. higher healthcare costsC. higher salariesD. improved safety for children Which of the following is NOT one of the three types of neurons?Group of answer choicesPeripheralSensory (or Afferent)Motor (or Efferent)Interneurons Can somebody plz give me the correct awnser if u dont know dont awnser it. We pay cash for this app. Ill give u brainlest Part BAnalyze Ramon's diet and find ways to make it healthier by providing suggestions for substitutions, eliminations, and reductions. By making theright changes, Ramon can bring down his fat and sugar intake and also keep on track with his total servings per food group for each day. Fill inyour suggestions for improving his Day 1 and Day 2 diet. UXXFont SizesA-A-DIEDay 1Substitutions Reductions EliminationFor breakfastFor lunchFor snacksFor dinnerDay 2Substitutions Reductions EliminationFor breakfastFor lunchFor snacksFor dinnerCharacters used: 223/ 15000632 PM 2.) Passive: The house is cleaned by my younger sister. Active: ___________________________. Rebecca goes into a restaurant with her five-year-old nieceand sits down. The niece seems fidgety and wants to eatbecause she is so hungry. Rebecca explain to her that theyneed to wait to order. She knows since this is not a fast foodrestaurant that they must first wait for their server to bringmenus. Next they have to give her their drink order. Saladswill be brought out, and when they are finished with thesalads, their dinners will be brought to the table. Finally,they will finish their meal with desserts. Is a diamond a homogeneous or heterogeneous mixture or a substance In the outline format below, the Arabic numeral 1 represents a(n):II.A.B.1.a.b.2.3 Which representation has a constant of variation of 2.5?Ax2345y57.51012.5B5 x + 2 y = 0Cy = negative 2.5 x + 1DOn a coordinate plane, a line goes through points (negative 1, 0) and (0, negative 2).ABCD Find the distance between the points(9,-7) and(5,-4). 255V137V7 HELP ME ITS MY LAST PROBLEM ITS PRECAL HELP MEEEE The parade marched down the street. It was led by a caped drummer. He set a stately pace and tapped the accompanying rhythm. A marching band followed behind him, matching his pace. Behind the band were floats of all sizes and designs. Children and adults were riding on the floats, tossing out penny candies, streamers, and plastic prizes. The street was lined with people. The noises of revelry filled the streets. Narrator's Perspective: please help. you can select a,b,c,d or multiple. Help please! i dont understand Factorise fully-x - 8 please do quick! will mark brainiest! a football field team lost 9 yards during a play the team had a combined gain or loss of 0 yards after the next play.what integer represents the yards gained or lost on the next play? plus help idk