In a simulation model, the subinterval method is used to compute batch averages. The transient period is estimated to be 100, and each batch has a time base of 100 time units as well. Using the following data, which provide the waiting times for customers as a function of the simulation time, estimate the 95% confidence interval for the mean waiting time.

Time interval 0-100 100-200 200-300 300-400 400-500 500-600 Waiting times 10, 20, 13, 14, 8, 15, 6, 8 12, 30, 10, 14, 16 15, 17, 20, 22 10, 20, 30, 15, 25, 31 15, 17, 20, 14, 13 25, 30, 15