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

Question

Quizplus · Accepted Answer

When the population standard deviation is unknown and the sample size is small (n < 30), the t distribution is used with n-1 degrees of freedom, which in this case is 24 (25-1).

From a Population That Is Normally Distributed with an Unknown μ\muμ

From a Population That Is Normally Distributed with an Unknown $\mu$