From a population that is normally distributed, a sample of 25 elements is selected and the standard deviation of the sample is computed. For the interval estimation of μ, the proper distribution to use is the
A) normal distribution.
B) t distribution with 25 degrees of freedom.
C) t distribution with 26 degrees of freedom.
D) t distribution with 24 degrees of freedom.

Question

Quizplus · Accepted Answer

When estimating the population mean μ from a sample, if the population standard deviation is unknown and the sample size is n, the t distribution with n-1 degrees of freedom is used. Here, n = 25, so n-1 = 24.

From a Population That Is Normally Distributed, a Sample of 25