Chapter 14, Problem 33E

Exercises 33 through 36 refer to the following story: The manufacturer of a new vitamin (vitamin X) decides to sponsor a study to determine the vitamin's effectiveness in curing the common cold. Five hundred college students having a cold were recruited from colleges in the San Diego area and were paid to participate as subjects in this study. The subjects were each given two tablets of vitamin X a day. Based on information provided by the subjects themselves, $457$ of the $500$ subjects were cured of their colds within $3$ days. (The average number of days a cold lasts is $4.87$ days.) As a result of this study, the manufacturer launched an advertising campaign based on the claim that “vitamin X is more than $90\%$ effective in curing the common cold.”

a. Describe as specifically as you can the target population for the study.

b. Describe the sampling frame for the study.

c. Describe the sample used for the study.