An FDA representative randomly selects 8 packages of ground chuck from a grocery store and measures the fat content

An FDA representative randomly selects 8 packages of ground chuck from a grocery store and measures the fat content (as a percent) of each package. Assume that the fat contents have an approximately normal distribution. The resulting measurements are given below.

Fat Contents (%)
19 18 11 17
17 19 12 15

Calculate the sample mean and the sample standard deviation of the fat contents. Round your answers to two decimal places, if necessary.
b. Construct a 95% confidence interval for the true mean fat content of all the packages of ground beef. Round the endpoints to two decimal places, if necessary.