Independent Simple Random Samples Are Taken to Test the Difference

Multiple Choice

Independent simple random samples are taken to test the difference between the means of two populations whose variances are known. The sample sizes are n₁ = 38 and n₂ = 42. The correct distribution to use is the

A) normal distribution
B) t distribution with 80 degrees of freedom
C) t distribution with 79 degrees of freedom
D) t distribution with 78 degrees of freedom