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

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Quizplus · Accepted Answer

When dealing with degrees of freedom in a t-test, it is acceptable to round to the nearest integer. This is because the t-distribution is continuous, and as the sample size increases, the distribution approaches normality, making the approximation of rounding to the nearest integer reasonable. Changing sample sizes or assuming equal variances when they are not can lead to inaccurate results. Therefore, rounding to the nearest integer is the recommended approach.

In Testing the Difference Between the Means of Two Normally