An airline wants to evaluate the depth perception of its pilots over the age of 50. A random sample of = 14 airline pilots over the age of 50 are asked to judge the distance between two markers placed 20 feet apart at the opposite end of the laboratory. The sample data listed here are the pilot's error (recorded in feet) in judging the distance. 2.7, 2.4, 1.9, 2.6, 2.4, 1.9, 2.3, 2.2, 2.5, 2.3, 1.8, 2.5, 2.0, 2.2

Compute the sample mean and the sample standard deviation, hence construct a 95% confidence interval on , the average error in depth perception for the company's pilots over the age of 50 (assume the sample is normally distributed and the critical value of t = 2.160)