Yoonie is a personnel manager in a large corporation. Each month she must review of the employees. From past experience, she has found that the reviews take her approximately four hours each to do with a population standard deviation of hours. Let Χ be the random variable representing the time it takes her to complete one review. Assume Χ is normally distributed. Let be the random variable representing the meantime to complete the reviews. Assume that the 16 reviews represent a random set of reviews.
Find the probability that the mean of a month’s reviews will take Yoonie from to hrs. Sketch the graph, labeling and scaling the horizontal axis. Shade the region corresponding to the probability.
a.

b. P(________________) = _______