Question 8.77

8.77 The new worker absence study

Refer to the previous exercise. Suppose you would like to do a new study next year to see if there has been a change in the percent of companies that do not measure how worker absences affect their company's bottom line. Assume that a new sample of 1234 companies will be used for the new study.

  1. Compute the 95% margin of error of the difference in proportions between the two studies for each of the following possible values of the sample proportion for the new study: (i) 0.36, (ii) 0.41, (iii) 0.46, and (iv) 0.51.
  2. Summarize your results with a graph.

    452

  3. Write a short summary describing what you have found in this exercise.

8.77

(a) (i) 0.0379. (ii) 0.0383. (iii) 0.0386. (iv) 0.0387. (c) As the second proportion increases (moves closer to 0.5), the margin of error of the difference in proportions increases somewhat, but note the change is not drastic due to the large sample size.