When you are testing whether two population means of two normally distributed populations differ and the population variances are both unknown but unequal, the t test statistics will usually have a non-integer number of degrees of freedom v.In this case, you should:
A) round down to the previous integer.
B) round up to the next integer.
C) assume that the population variances are equal and use v = n1 + n2 - 2.
D) change the sample sizes until the number of degrees of freedom is an integer.

Question

Quizplus · Accepted Answer

When dealing with a t-test where the population variances are unknown and assumed to be unequal (Welch's t-test), the calculation of the degrees of freedom often results in a non-integer value. The conventional approach is to round down to the nearest whole number to be conservative in the hypothesis testing process.

When You Are Testing Whether Two Population Means of Two