The personnel department of ZTel, a large communication company, is reconsidering its

hiring policy. Each applicant for a job must take a standard exam and to hire or no hire

decision depends at least in part on the result of the exam. The scores of all applicants

have been examined closely. They are approximately normally distributed with mean 525

and standard deviation 55.

The current hiring policy occurs in two phase. The first phase separates all applicants into

three categories: automatic accepts, automatic rejects and maybe. The automatic accepts

are those whose test scores are 600 or above. The automatic rejects are those whose test

scores are 425 and below. All other applicants (the maybes) are passed on to the second

phase where their previous job experience, special talents, and other factors are used as

hiring criteria. The personnel manager at ZTel wants to calculate the percentage of

applicants who are automatic accepts or rejects, given the current standards. She also

wants to know how to change the standards to automatically reject 10% of all applicants

and automatically accept 15% of all applicants.