Question

Thirty-nine randomly selected students in a college took the stat final. The sample mean was 68.9 with standard deviation 8.3 . The 99% confidence interval estimate of the population mean is:

Answer 1

(65.5775 , 72.2225)

Explanation:

Confidence Interval is the range around sample mean, likely to consist the population parameter.

Formula = x' + z (s / √n)

= 68.9 + 2.5 (8.3 / √39)

= 68.9 + 3.3225

(65.5775 , 72.2225)