The personnel director of a large firm administers a skills test to all applicants for job positions within the computer department.  Scores range from 0 to 100.  Using Excel, the administrator formed the histogram for all scores over a 10 year period.  From this chart, she decided the scores were bell-shaped.  The scores are listed in Skillscores.xls.

1.  Verify the bell-shaped distribution.  Use bins of 40,50,60,...,100.

2. What is the mean of this population of scores? (Round one place past the decimal.)

3. What is the standard deviation of this population? (Round one place past the decimal--be sure you use population.)

4. The empirical rule tells us what to expect from bell-shaped data.  Check the data for a bell-shaped distribution using the empricial rule.  Do the results seem to confirm or deny this description of the data?  Explain.

Work the following problems using the empirical rule.  Assume the distribution is bell-shaped.

5. a. If she decides that only applicants who score more than 79.6 will qualify for a position, what percent of applicants will qualify?
    b. If she wants to have 10 qualified applicants to choose from, how many people would she like to have apply and take the test?

6. If applicants who score more than 60 can usually perform jobs in teh computer department, what percent of applicants will meet this standard?

7. Applicants between 50.2 and 79.6 seem to be best a a certain group of tasks.  What percent fall in this group?

8. What percent of applicants score between 79.6 and 89.4?

9. If she will only take the top 2.5% of applicants, what must an applicant score to qualify?