Listed below are arrival delays (minutes) of randomly selected American Airlines flights from New York (JFK) to

Question:

Listed below are arrival delays (minutes) of randomly selected American Airlines flights from New York (JFK) to Los Angeles (LAX). Negative numbers correspond to flights that arrived before the scheduled arrival time. Use a 95% confidence interval. How good is the on-time performance?
-5 -32 -13 -9 -19 49 -30 -23 14 -21 -32 11
Construct the confidence interval estimate of the mean.