Microsoft KB Archive/102818

t-Test Assuming Unequal Variance Returns Incorrect DF Value Last reviewed: September 12, 1996 Article ID: Q102818

The information in this article applies to: Microsoft Excel for Windows, versions 4.0, 4.0a SYMPTOMS In Microsoft Excel, when you use the Analysis ToolPak t-Test: Two-Sample Assuming Unequal Variances function or tool, the degree of freedom (df) that is returned is incorrect. Degree of freedom should be a whole number. The two-sample assuming unequal variances returns a decimal (real) number. STATUS Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem has been corrected in Microsoft Excel version 5.0. MORE INFORMATION The t-Test: Two-Sample Assuming Unequal Variances tool performs a two-sample student's t-test. This form of the test assumes that the variances of both ranges of data are unequal and is referred to as a heteroscedastic t-test. When to use a t-test Use a t-test to determine whether two sample means are equal. Use this test when the groups under study are distinct. Use a paired test when there is one group before and after a treatment.

KBCategory: kbusage kbtool KBSubcategory: Additional reference words: 4.00 4.00a ttest pttestv atp pack integer Last reviewed: September 12, 1996 © 1998 Microsoft Corporation. All rights reserved. Terms of Use.