When the population is normally distributed, population standard deviation σ is unknown, and the sample size is n = 15, the confidence interval for the population mean μ is based on
A) the z (normal) distribution.
B) the t distribution.
C) the binomial distribution.
D) the Poisson distribution.
E) None of these answers is correct.

Question

Quizplus · Accepted Answer

When the standard deviation is unknown, you have to use the t distribution because you have to approximate the standard deviation with that formula.

When the Population Is Normally Distributed, Population Standard Deviation σ