A random sample of 64 students at a university showed an average age of 25 years and a sample standard deviation of 2 years.The 98% confidence interval for the true average age of all students in the university is
A) 20.5 to 29.5.
B) 24.4 to 25.6.
C) 23.0 to 27.0.
D) 20.0 to 30.0.

Question

Quizplus · Accepted Answer

The 98% confidence interval is calculated using the formula: mean ± (z * (standard deviation/√n)). Here, the mean is 25, the standard deviation is 2, n is 64, and the z-value for 98% confidence is approximately 2.33. This gives the interval 25 ± (2.33 * (2/√64)) = 24.4 to 25.6.

A Random Sample of 64 Students at a University Showed