試題詳解

15. In testing the difference between the means of two normally distributed populations, the nunbet of degrees of freedom associated with the unequa sal-variances t-test statistic usually results in a non-integer number. It is r recommended that you:
(A) round to the nearest integer.
(B) chunge the sample sizes until the number of degrees of frocdom becomes an inteyer.
(C) assume that the population variances are equal, and then use df= n₁ + n₂ -2
(D) None of these choices.