If we change a 95% confidence interval estimate to a 99% confidence interval estimate, we can expect the
A) width of the confidence interval to increase.
B) width of the confidence interval to decrease.
C) width of the confidence interval to remain the same.
D) sample size to increase.

Question

Quizplus · Accepted Answer

Increasing the confidence level from 95% to 99% means we are increasing the level of certainty in the estimate. To attain a higher level of certainty, we require more area in the tail ends of the distribution, which leads to a wider interval. Hence, the width of the confidence interval will increase.

If We Change a 95% Confidence Interval Estimate to a 99