An industrial engineer is conducting a time study for a work element. The select time is 4.5 minutes, and the sample standard deviation of the observed time is 20 seconds. What is the appropriate...

An industrial engineer is conducting a time study for a work element. The select time is 4.5 minutes, and the sample standard deviation of the observed time is 20 seconds. What is the appropriate sample size if the estimate is to be 5 percent of the true average time 95 percent of the time?