The width of a confidence interval estimate of the population mean increases when the:
A)level of confidence increases
B)sample size decreases
C)value of the population standard deviation increases
D)All of these choices are true.

Question

Quizplus · Accepted Answer

The width of a confidence interval estimate of the population mean is calculated according to the level of confidence, sample size, and population standard deviation.

A) When the level of confidence increases, the width of the confidence interval also increases.

B) When the sample size decreases, the width of the confidence interval also increases because smaller sample sizes result in less precise estimates.

C) When the value of the population standard deviation increases, the width of the confidence interval also increases as it indicates more variability in the population.

Therefore, all of these choices are true, and the best answer is D.

The Width of a Confidence Interval Estimate of the Population