What conditions are necessary to use the t-test for testing th...

Question

What conditions are necessary to use the t-test for testing the difference between two population means?

Accepted Answer

Mm Hi everybody and welcome back. Our next problem says, which of the following is not a required assumption for performing a two-sample T test for the difference in means. A. The samples are dependent. The populations are normally distributed. The data are measured on an interval or ratio scale, or D, the population variances are equal for the pooled T test. So one of these should jump right out at you, because if we're doing this two sample T tests for a difference in means, we do need to have independent samples as a as a ground level assumption. So, choice A will be our answer, as since we want the samples to be independent, having dependent samples is not a requirement. Two of these others are also fairly straightforward. Uh choice B, the populations are normally distributed. This is a required assumption, therefore not our answer. Either normally distributed, or this also works if the sample size of both populations is greater than or equal to 30. Which will mean your distribution of your values is going to be close enough to a normal distribution. And in choice C, the data are measured on an interval or ratio scale, referring to the way the data are measured. Interval or ratio scale are needed to be able to make meaningful. Mathematical comparisons between the values and the way that they are measured. So, can you measure meaningful differences between the values, since we're using these differences as the basis of our calculation. So that is also a required assumption. And then finally, choice D, the population variances are equal for the pooled T test, and this is correct. Recall that we have two different types of a 2 sample T test, but if we want to use the pooled version, Then the population variances need to be equal, but to use the pooled T test. So, this is also a required assumption, although it's phrased a little bit in a funny way, since it required since it refers to an assumption on one type of tea test, but it's a true statement about something that is assumed. So, again, we're asked about which is not a required assumption for performing a two sample T test for the difference in means, and that is choice A, the samples are dependent. See you in the next video.

��app