Consider the following problem:

The grade point averages for 12 randomly selected students are shown in the table below. Find the 99% confidence interval around the population mean, µ. Assume the population is normally distributed.

Solution:

Because this is a small sample, n < 30, and we do not know sigma, use the t-distribution.

The Excel solution is: [Read more…] about Single-Sample, Small Sample, Confidence Interval for a Mean