When you estimate a population proportion by sample, which of the following will make the confidence interval narrower?
A) increase the confidence level
B) increase the sample proportion
C) increase the margin of error
D) increase the sample size

Question

Quizplus · Accepted Answer

Increasing the sample size will make the confidence interval narrower since it reduces the standard error of the estimate. The larger the sample size is, the more likely it is to accurately reflect the population proportion. On the other hand, increasing the confidence level or the margin of error will make the confidence interval wider. Increasing the sample proportion does not necessarily affect the width of the confidence interval.

When You Estimate a Population Proportion by Sample, Which of the Following