An entertainment company is in the planning stages of producing a new computer-animated movie for national release, so they need to determine the production time (in labor-hours) necessary to produce the movie. The mean production time for a random sample of 21 big-screen computer animated movies is 48,600 labor-hours, with a standard deviation of 6,570. Required:
a. Determine the sample mean, sample standard deviation, and sample size.
b. Determine the critical value that corresponds to the 90% level of confidence, and compute the margin of error, m.
c. Give the 90% confidence interval. Interpret your confidence interval in context.