When making a statistical inference about the mean of a normally distributed population based on a sample drawn from that population, which of the following statements is correct, all else being equal?
Answer
A
The 68% confidence interval is wider than the 90% confidence interval.
B
The 90% confidence interval is narrower than the 95% confidence interval.
C
The 90% confidence interval is wider than the 99% confidence interval.
D
The 99% confidence interval is narrower than the 68% confidence interval.
Explanation
With the same sample and other conditions held constant, a higher confidence level requires a wider interval to increase the chance that it captures the population mean. Thus, the 95% confidence interval is wider than the 90% confidence interval, so the statement that the 90% interval is narrower than the 95% interval is correct.
AI-written and checked against the verified answer.