In which of the following situations do we use the t distrib

In which of the following situations do we use the t distribution in the calculation of confidence intervals? When the data are: a. not normally distributed, b. not mutually exclusive, c. normally distributed, d. mutually exclusive.

Solution

OPITON A: Not normally distributed.
**********************

When we do a test for sample means, by central limit theorem, the sampling distirbution will be ONLY approximately normally distributed. However, to compensate for what we do not know about the population, we use t distribution instead of z.