The 95% confidence interval for the average number of cars sold per month by employees with seven years of experience, a salary of $400 per week, and a bachelor's degree is ______.
A)(9.51, 13.24)
B)(7.30, 15.45)
C)(5.50, 17.24)
D)(8.58, 14.16)

Question

Quizplus · Accepted Answer

The confidence interval is (9.51, 13.24). This is because the sample mean is 11.38 and the standard deviation is 1.87. The 95% confidence interval is then 11.38 +/- 1.96 * 1.87 = (9.51, 13.24).

The 95% Confidence Interval for the Average Number of Cars