Suppose a 95% confidence interval for µ turns out to be (1,000, 2,100). To make more useful inferences from the data, it is desired to reduce the width of the confidence interval. Which of the following will result in a reduced interval width?
A) increase the sample size
B) increase the sample mean
C) increase the population mean
D) increase the confidence level

Question

Quizplus · Accepted Answer

Increasing the sample size will decrease the standard error and increase the precision of the estimate, resulting in a narrower confidence interval. Increasing the sample mean, population mean, or confidence level will all result in wider confidence intervals.

Suppose a 95% Confidence Interval for µ Turns Out to Be