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

Multiple Choice

At a particular 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]