A random sample of 16 passenger fares on Amtrak between Chic…

A rаndоm sаmple оf 16 pаssenger fares оn Amtrak between Chicago and Denver resulted in a mean fare of $180 and a standard deviation of $40. We are interested in estimating the Confidence Interval on the true "Population Mean" fare between Chicago and Denver on Amtrak. What is the "Sample Size" in this problem?