Question 7.125

7.125 Testing job applicants.

The one-hole test is used to test the manipulative skill of job applicants. This test requires subjects to grasp a pin, move it to a hole, insert it, and return for another pin. The score on the test is the number of pins inserted in a fixed time interval. One study compared male college students with experienced female industrial workers. Here are the data for the first minute of the test:45

Group
Students 750 35.12 4.31
Workers 412 37.32 3.83
  1. We expect that the experienced workers will outperform the students, at least during the first minute, before learning occurs. State the hypotheses for a statistical test of this expectation and perform the test. Give a -value, and state your conclusions.
  2. The distribution of scores is slightly skewed to the left. Explain why the procedure you used in part (a) is nonetheless acceptable.
  3. One purpose of the study was to develop performance norms for job applicants. Based on the preceding data, what is the range that covers the middle 95% of experienced workers? (Be careful! This is not the same as a 95% confidence interval for the mean score of experienced workers.)

  4. The five-number summary of the distribution of scores among the workers is

    23 33.5 37 40.5 46

    for the first minute and

    32 39 44 49 59

    for the fifteenth minute of the test. Display these summaries graphically, and describe briefly the differences between the distributions of scores in the first and fifteenth minutes.

416

7.125

(a) . There is significant evidence that the experienced workers will outperform the students during the first minute. (b) Because , the procedures can be used for skewed data. (c) 29.66 and 44.98. (d) The scores for the 1st minute are much lower than the scores for the 15th minute.