The U.S. Centers for Disease Control recommends that adults engage in 2.5 hours per week of vigorous exercise. A local health society conducts a survey to see if people are meeting this goal. They ask 100 people with gym memberships how many minutes of exercise they engage in per week. After analyzing the data, the health society finds that the average respondent exercises 142 minutes per week, but the margin of error was approximately 36 minutes. The society wants to lower this margin of error. Using which of the following samples instead would do so?
A. 50 people with gym memberships
B. 50 people randomly selected from the entire adult population
C. 100 people with gym memberships, but from a variety of gyms
D. 200 people randomly selected from the entire adult population
Answer:D
The U.S. Centers for Disease Control recommends that adults engage in 2.5 hours per week of vigorous exercise. A local health society conducts a survey to see if people are meeting this goal. They ask 100 people with gym memberships how many minutes of exercise they engage in per week. After analyzing the data, the health society finds that the average respondent exercises 142 minutes per week, but the margin of error was approximately 36 minutes. The society wants to lower this margin of error. Using which of the following samples instead would do so?
A. 50 people with gym memberships B. 50 people randomly selected from the entire adult population C. 100 people with gym memberships, but from a variety of gyms D. 200 people randomly selected from the entire adult population
Explanation: D