It was found that in a sample of 90 teenage boys, 70% of them have received speeding tickets. What is the 90% confidence interval of the
A) 0.620

Question

It was found that in a sample of 90 teenage boys, 70% of them have received speeding tickets. What is the 90% confidence interval of the
A) 0.620 < p < 0.780
B) 0.591 < p < 0.812
C) 0.584 < p < 0.830
D) 0.615 < p < 0.805

Quizplus · Accepted Answer

The 90% confidence interval is calculated as:p +/- 1.645 * sqrt((p * (1 - p)) / n)where p is the sample proportion, and n is the sample size.Plugging in the values we get:0.7 +/- 1.645 * sqrt((0.7 * (1 - 0.7)) / 90)= 0.7 +/- 0.08= (0.620, 0.780)Therefore, the correct answer is A.

It Was Found That in a Sample of 90 Teenage