Confidence Interval for single proportion.
A study was conducted to investigate drinking problems among college students. In 1983, a group of students were asked whether they had ever driven an automobile as drinking. In 1987 after legal drinking age was raised, a different group of college students were asked the same problem. The results are as follows.
Drove While Drinking

Year

Total

1983

1987

Yes

1250

991

2241

No

1387

1666

3053

Total

2637

2657

5294

Compute separately for 1983 and 1987, the 95% confidence interval for the proportion of students who had driven an automobile while drinking.