/*! 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} Problem 69 How does the value of \(\sigma_{... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

How does the value of \(\sigma_{\hat{p}}\) change as the sample size increases? Explain. Assume \(n / N \leq .05\).

Short Answer

Expert verified
The value of \(\sigma_{\hat{p}}\) decreases as the sample size (n) increases. This is because increasing the sample size provides a better estimate of the population proportion, which results in a decrease in its variability around \(p\), and hence a smaller standard error.

Step by step solution

01

Identify the formula for \(\sigma_{\hat{p}}\)

The standard error of the proportion is calculated by the formula: \(\sigma_{\hat{p}} = \sqrt{\frac{p(1 - p)}{n}}\), where \(p\) is the population proportion and \(n\) is the sample size
02

Explain the relationship between \(\sigma_{\hat{p}}\) and n

Looking at the formula for \(\sigma_{\hat{p}}\), we can see that the sample size (n) is in the denominator of the fraction under the square root. This means that as \(n\) increases, the value of the fraction decreases, which in turn means the square root of the fraction (and hence \(\sigma_{\hat{p}}\)) decreases. So, t increase in sample size (n) would cause a decrease in the standard error (\(\sigma_{\hat{p}}\)).
03

Explain the reason for this relationship

The reason behind the relationship between standard error for the population proportion and sample size is that increasing the sample size gives us a better estimate of the population proportion. Thus, the variability of \(\hat{p}\) around \(p\) decreases, which is reflected in a smaller standard error.

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

A population has a normal distribution. A sample of size \(n\) is selected from this population. Describe the shape of the sampling distribution of the sample mean for each of the following cases. a. \(n=23\) b. \(n=450\)

For a population, \(\mu=125\) and \(\sigma=36\). a. For a sample selected from this population, \(\mu_{\bar{x}}=125\) and \(\sigma_{\bar{x}}=3.6 .\) Find the sample size. Assume \(n / N \leq .05\). b. For a sample selected from this population, \(\mu_{\bar{x}}=125\) and \(\sigma_{\bar{x}}=2.25 .\) Find the sample size. Assume \(n / N \leq .05\).

Refer to Exercise 7.79. Beginning in the second half of 2011 , there were widespread protests in many American cities that were primarily against Wall Street corruption and the gap between the rich and the poor in America. According to a Time Magazine/ABT SRBI poll conducted by telephone during October \(9-10,2011,86 \%\) of adults who were familiar with those protests agreed that Wall Street and lobbyists have too much influence in Washington (The New York Times, October 22, 2011). Assume that this percentage is true for the current population of American adults. Let \(\hat{p}\) be the proportion in a random sample of 400 American adults who hold the opinion that Wall Street and lobbyists have too much influence in Washington. Find the probability that the value of \(\hat{p}\) will be a. greater than \(.88\) b. between \(.82\) and 84

The GPAs of all 5540 students enrolled at a university have an approximately normal distribution with a mean of \(3.02\) and a standard deviation of \(.29 .\) Let \(\bar{x}\) be the mean GPA of a random sample of 48 students selected from this university. Find the mean and standard deviation of \(\bar{x}\), and comment on the shape of its sampling distribution.

A city is planning to build a hydroelectric power plant. A local newspaper found that \(53 \%\) of the voters in this city favor the construction of this plant. Assume that this result holds true for the population of all voters in this city. a. What is the probability that more than \(50 \%\) of the voters in a random sample of 200 voters selected from this city will favor the construction of this plant? b. A politician would like to take a random sample of voters in which more than \(50 \%\) would favor the plant construction. How large a sample should be selected so that the politician is \(95 \%\) sure of this outcome?

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.