Two groups were polled about their attitudes towards capital punishment. In one group 30 out of 100 favored capital punishment, and in the other group 40 out of 80 favored capital punishment. Calculate an appropriate test value test the hypothesis that the population proportions are the same.
A) -2.73
B) -37.40
C) -0.20
D) -13.68

Question

Quizplus · Accepted Answer

The test value is calculated using the formula for the difference between two proportions. The pooled proportion is used to find the standard error, and then the z-score is calculated. The correct z-score is approximately -2.73.

Two Groups Were Polled About Their Attitudes Towards Capital Punishment