A basketball scout randomly selected 144 players and timed how long each player took to perform a certain drill. The times in this sample were distributed with a mean of 8 minutes. The population standard deviation was known to be 3 minutes.

A. find the critical value for a 95% confidence interval for the population mean of drill times.

B. Using 95% confidence interval, estimate the population mean of drill time.

1 answer

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability ([1-.95]/2 = .05/2 = .025) and its Z score.

A. 95% = mean ± 1.96 SEm

SEm = SD/√n