1. Let's assume the manager of a fixed-base operator (FBO) asked the pilots who used the FBO's services to specify their age. After collecting data for 6 months, the results approximated a normal distribution with a mean of 43 years and a standard deviation of 6 years. Based on these data, the manager decided to play music inside the FBO fa- cility that catered to the 37- to 49-year-old age group. On what basis did the manager make this decision?