The National AIDS Behavioral Surveys interviewed a sample of adults in the cities where AIDS is most common. This sample included 803 heterosexuals who reported having more than one sexual partner in the past year. We can consider this an SRS of size 803 from the population of all heterosexuals in high-risk cities who have multiple partners. These people risk infection with the AIDS virus. Yet 304 of the respondents said they never use condoms. a. Is this strong evidence that more than one-third of this population never use condoms?
b. What is the sample proportion of heterosexuals in high-risk who never use condoms? Give your answer to 4 decimal places.