A basketball coach wants to know how many free throws an NBA player shoots during the course of an average practice. The coach takes a random sample of 43 players and finds the average number of free throws shot per practice was 225 with a standard deviation of 35. Construct a 99% confidence interval for the average number of free throws in practice.
A) [210.5992, 239.4008]
B) [210.6155, 239.3845]
C) [211.2506, 238.7494]
D) [214.2290, 235.7710]

Question

Quizplus · Accepted Answer

The 99% confidence interval is calculated using the formula for a confidence interval for a mean, which includes the sample mean, the standard deviation, and the critical value from the t-distribution (since the population standard deviation is unknown and the sample size is less than 30). The correct interval, [210.5992, 239.4008], accounts for the variability in the sample mean and the level of confidence desired.

A Basketball Coach Wants to Know How Many Free Throws