Iman (1994, p. 505) presents data on how college students and experts perceive risks for 30 activities or technologies. Each group ranked the 30 activities. The rankings for the eight greatest risks, as perceived by the experts, are shown in Table 11.5.
a. Prepare a scatterplot of the data, with stu­dents’ ranks on the vertical axis and experts’ ranks on the horizontal axis.
b. The correlation between the two sets of ranks is .407. Based on your scatterplot in part (a), do you think the correlation would increase or decrease if X rays were deleted? Explain. What if pesticides were deleted instead?
c. Another technology listed was nuclear power, ranked first by the students and 20th by the experts. If nuclear power was added to the list, do you think the correlation between the two sets of rankings would increase or decrease? Explain.