In order to construct a 95% confidence interval for the population mean when the population standard deviation is unknown and the sample size is 15, you should use the t-value indicated as:
A) t0.10,15
B) t0.10,14
C) t0.05,15
D) t0.05,14
E) t0.025,14

Question

Quizplus · Accepted Answer

When the population standard deviation is unknown and the sample size is small (n < 30), the t-distribution is used. For a 95% confidence interval, the alpha level is 0.05, and since it's two-tailed, you look for t0.025 with degrees of freedom equal to n-1, which is 14.

In Order to Construct a 95% Confidence Interval for the Population