Question

From public records, individuals were identified as having been charged with drunken driving not less than 6 months or more than 12 months from the starting date of the study. Two random samples from this group were studied. In the first sample of 30 individuals, the respondents were asked in a face-to-face interview if they had been charged with drunken driving in the last 12 months. Of these 30 people interviewed face to face, 14 answered the question accurately. The second random sample consisted of 41 people who had been charged with drunken driving. During a telephone interview, 26 of these responded accurately to the question asking if they had been charged with drunken driving during the past 12 months. Assume the samples are representative of all people recently charged with drunken driving.

Let p₁ represent the population proportion of all people with recent charges of drunken driving who respond accurately to a face-to-face interview asking if they have been charged with drunken driving during the past 12 months. Let p₂ represent the population proportion of all people who respond accurately to the question when it is asked in a telephone interview. Find a 90% confidence interval for p₁ – p₂. (Use 3 decimal places.)

Upper Limit =

Lower Limit =

Answer 1