Suppose you want to find an estimate for the population mean age of customers. You take a sample of 25 customers and find that the sample mean age is 28 years. You do not know what the population standard deviation is, but the sample standard deviation is 2.6.

Which statement is true about a confidence interval for the population mean age of customers?

A confidence interval for the population mean will use a standard normal distribution to find a z-score.
A confidence interval for the population mean will use a t distribution to find a t-score.