/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. 7. 13 According to government data, 22... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

According to government data, 22% of American children under the age of 6 live in households with incomes less than the official poverty level. A study of learning in early childhood chooses an SRS of 300 children from one state and finds that p∧p^=0.29.

a. Find the probability that at least 29% of the sample are from poverty-level households, assuming that 22% of all children under the age of 6 in this state live in poverty-level households.

b. Based on your answer to part (a), is there convincing evidence that the percentage of children under the age of 6 living in households with incomes less than the official poverty level in this state is greater than the national value of 22%? Explain your reasoning.

Short Answer

Expert verified

a. The resultant probability is 0.17%

b. The resultant statement greater than the national value of 22% is true.

Step by step solution

01

Part (a) Step 1: Given Information

The given probability is p=22%=0.22

n=50p^=0.29

The following formula was used:

σp^=p(1−p)nz=x−μσ

02

Part (a) Step 2: Calculations

Consider that

μp^=p=22%=0.22

The standard deviation of the sample population's sampling distribution is p^

role="math" localid="1654353485299" σp^=p(1−p)n=0.22(1−0.22)300=0.0239

The z-result is

role="math" localid="1654353515716" z=x−μσ=0.29−0.220.0239=2.93

The normal probability formula is:

Pp^≥0.29=P(Z>2.93)=1−P(Z<2.93)=1−0.9983=0.0017=0.17%

03

Part (b) Step 1: Given Information

The given probability is p=22%=0.22

n=50p^=0.29

The following formula was used:

σp^=p(1−p)nz=x−μσ

04

Part (b) Step 2: Calculations

Consider that

μp^=p=22%=0.22

The standard deviation of the sample population's sampling distribution is p^

σp^=p(1−p)n=0.22(1−0.22)300=0.0239

The z-result is

z=x−μσ=0.29−0.220.0239=2.93

The normal probability formula is:

Pp^≥0.29=P(Z>2.93)=1−P(Z<2.93)=1−0.9983=0.0017=0.17%

When the likelihood is less than 0.05, the probability is said to be small.

In this situation, the chance is really low, therefore getting at least 29 percent housed holds is implausible. This implies there is strong evidence that the percentage of children under the age of six living in households with earnings below the official poverty level in this state is higher than the national average of 22%.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Sample proportions List all 10possible SRSs of size n=2, calculate the proportion of females for each sample, and display the sampling distribution of the sample proportion on a dotplot.

Bias and variability The figure shows approximate sampling distributions of 4different

statistics intended to estimate the same parameter.




a. Which statistics are unbiased estimators? Justify your answer.

b. Which statistic does the best job of estimating the parameter? Explain your answer.

A researcher initially plans to take an SRS of size 160 from a certain population and calculate the sample mean x-x¯. Later, the researcher decides to increase the sample size so that the standard deviation of the sampling distribution of x-x¯will be half as big as when using a sample size of 160 . What sample size should the researcher use?

a. 40

b. 80

c. 320

d. 640

e. There is not enough information to determine the sample size.

The number of undergraduates at Johns Hopkins University is approximately 2000 , while the number at Ohio State University is approximately 60,000. At both schools, a simple random sample of about 3%of the undergraduates is taken. Each sample is used to estimate the proportion p of all students at that university who own an iPod. Suppose that, in fact, p=0.80 at both schools. Which of the following is the best conclusion?

a. We expect that the estimate from Johns Hopkins will be closer to the truth than the estimate from Ohio State because it comes from a smaller population.

b. We expect that the estimate from Johns Hopkins will be closer to the truth than the estimate from Ohio State because it is based on a smaller sample size.

c. We expect that the estimate from Ohio State will be closer to the truth than the estimate from Johns Hopkins because it comes from a larger population.

d. We expect that the estimate from Ohio State will be closer to the truth than the estimate from Johns Hopkins because it is based on a larger sample size.

e. We expect that the estimate from Johns Hopkins will be about the same distance from the truth as the estimate from Ohio State because both samples are 3 % of their populations.

10%Why is it important to check the 10 % condition before calculating probabilities involving localid="1654670795605">x-?

a. To reduce the variability of the sampling distribution of x-x¯

b. To ensure that the distribution of x-x¯is approximately Normal

c. To ensure that we can generalize the results to a larger population

d. To ensure that x-x¯will be an unbiased estimator of μ

e. To ensure that the observations in the sample are close to independent

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.