At an Academically Challenging High School, the Average GPA of a High

Multiple Choice

At an academically challenging high school, the average GPA of a high school senior is known to be normally distributed with a variance of 0.25. A sample of 20 seniors is taken and their average GPA is found to be 2.71. Develop a 90% confidence interval for the population mean GPA.

A) [2.5261, 2.8939]
B) [2.5667, 2.8533]
C) [2.6180, 2.8020]
D) [2.6384, 2.7816]