Question

A graduate student wanted to estimate the average time spent studying among graduate students at her school. She randomly sampled graduate students from her school and obtained a 99% confidence interval of (17,25) hours/week. Which of the following would be true if the level of confidence was lowered to 95%? Choose the correct answer below.A. The width of the confidence interval would remain the same.B. The width of the confidence interval would be smaller.C. The width of the confidence interval would be larger.D. More information is needed to determine what would happen to the width of the confidence interval.

Answer 1

B. The width of the confidence interval would be smaller.

Explanation:

By reducing the confidence level from 99% to 95%, the student assumes that there is more uncertainty about the new confidence interval than the previous one. That, being said, since the results aren't as certain, the confidence interval is widened towards a central average point because the new interval isn't as accurate.

Therefore, the answer is B. The width of the confidence interval would be smaller.