To compute an interval estimate for difference between the m

To compute an interval estimate for difference between the means of two populations, the t-distribution should be used if

Select one:

A. the populations are normally distributed

B. the population variances are unknown

C. both a and b are satisfied

D. the population means are equal

E. None of the above answers is correct

Solution

t-distribution is used to the normally distributed random variable whose sample size is less than 30 and the population variance is unknown.

therefore option C is correct.