We Sampled 100 Men and 100 Women and Asked: "Do

Multiple Choice

We sampled 100 men and 100 women and asked: "Do you think the environment is a major concern?" Of those sampled, 67 women and 53 men responded that they believed it is. For the confidence interval procedure to work properly, what additional assumptions must be satisfied?

A) Both populations have approximate normal distributions.
B) Both samples were randomly and independently selected from their respective populations.
C) The population variances are equal.
D) All of the above are necessary.