Question

The reason we use t procedures instead of $z$ procedures when carrying out a test about a population mean is that

a. z requires that the sample size be large.

b. z requires that you know the population standard deviation $\sigma$

c. z requires that the data come from a random sample.

d. z requires that the population distribution be Normal.

e. z can only be used for proportions.

Short answer

The correct option is (b).

Step-by-step solution

Given information

When doing a test on a population mean, we employ $t$ procedures rather than $z$ procedures for several reasons.

Explanation

The best answer for the given statement is “ $z$ requires that you know the population standard deviation $\sigma$”. So the correct option is (b).