A random sample of 139 forty-year-old men contains 26% smokers. Use Table 5.1 to estimate the P- value for a test of the claim that the percentage of forty-year-old men that smoke is 22%.
A) 0.2542
B) 0.1401
C) 0.2802
D) 0.1271

Question

Quizplus · Accepted Answer

The P-value is the area under the normal curve that is to the right of the z-score for the sample proportion. The z-score for the sample proportion is (0.26 - 0.22) / sqrt(0.22 * 0.78 / 139) = 2.54. The area to the right of this z-score is 0.0054, which is the P-value.

A Random Sample of 139 Forty-Year-Old Men Contains 26% Smokers