1. A clinical psychologist wants to estimate the average reaction time to a stimulus among N = 250 patients in a hospital specializing in nervous disorders. A simple random sample of n = 20 patients was selected, and their reaction times were measured, with the following results: = 2.1 seconds, s= 0.4 seconds Determine how large a sample should be taken in order to estimate the population mean, , with a bound on the error of estimation, B, of 1.0 seconds. Use 1.0 seconds as an approximation of the population standard deviation, .