Worker Fatigue. A study by M.Chen et al. titled “Heat Stress Evaluation and Worker Fatigue in a Steel Plant” (American Industrial Hygiene Association, Vol. 64, pp. 352–359) assessed fatigue in steel-plant workers due to heat stress. If the mean post-work systolic pressure for electric arc-melting workers equals the normal systolic pressure of 120 mmHg, find the probability that a random sample of 29 electric arc-melting workers will have a mean post-work systolic pressure exceeding 126.1 mmHg. Assume that the population standard deviation of post-work systolic pressure for electric arc-melting workers is 12.1 mmHg. State any assumptions that you are making in solving this problem.

Extending the Concepts and Skills