Suppose a Survey Is Taken of Two Groups of People

Multiple Choice

Suppose a survey is taken of two groups of people where each person is asked a yes/no question and the proportion of people who answer yes is calculated for each group. Which of the following is true about a hypothesis test of the difference in the two proportions?

A) Normality can be assumed if the sample size for each population is at least 30.
B) The t-distribution should be used if the standard deviations are unknown.
C) The standard deviation must be assumed equal.
D) Normality can be assumed if, in each group, at least 5 people say yes, and at 5 people say no.