A random sample of 36 students at a community college showed an average age of 25 years. Assume the ages of all students at the college are normally distributed with a standard deviation of 1.8 years. The 98% confidence interval for the average age of all students at this college is _____.
A) 24.301 to 25.699
B) 24.385 to 25.615
C) 23.200 to 26.800
D) 23.236 to 26.764

Question

Quizplus · Accepted Answer

The correct answer is A because the 98% confidence interval for the average age of all students at this college is 24.301 to 25.699. This is calculated using the formula: sample mean +/- (z-score * standard deviation / square root of sample size). The z-score for a 98% confidence interval is 2.326.

A Random Sample of 36 Students at a Community College