Question

From a normally distributed population, a simple random sample of size 30 is taken. The mean of the sample is 144 and the standard deviation of the sample is 12.
Construct a 90% confidence interval for the population mean.

A. (139.7, 148.3)
B. (140.4, 147.6)
C. (142.4, 145.6)
D. (143.3, 144.7)

Answer 1

From a normally distributed population, a simple random sample of size 30 is taken. The mean of the sample is 144 and the standard deviation of the sample is 12.

Construct a 90% confidence interval for the population mean.

Solution: B. (140.4, 147.6)