Two sample unequal variance t test3/12/2024 ![]() In turn that means your confidence interval is usually a bit narrower and you are more likely to be able to reject the null hypothesis. Higher degrees of freedom translate to a higher critical t and lower p-value. (Note: population variances, not sample variances.) Tha is usually (not always) a bit higher than the degrees of freedom computed by the general formula. However, if you know that the population variances are equal, you can use df = n 1 + n 2 − 2. For two-sample inferences, the general formula for degrees of freedom is shown at right. As you know, there are an infinite number of t distributions, each one determined by its degrees of freedom. The sampling distribution of the difference of sample means follows a Student's t distribution. Unless you want more details, you can stop reading now. Here's the short answer: just use the Unequal Variances column. StatTools gives two columns of results, headed "Equal Variances" and "Unequal Variances". In StatTools, I'm selecting a confidence interval or hypothesis test about the difference in means of two independent samples. "Equal Variances" and "Unequal Variances" in Two-Sample Inferences "Equal Variances" and "Unequal Variances" in Two-Sample Inferencesġ7.11.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |