Provides answers to commonly asked questions about COBRA. Health Benefits Under the Consolidated Omnibus Budget Reconciliation Act (COBRA) (PDF) Provides a detailed overview of the major provisions of COBRA.
In the two-sample pooled t-test the pooled variance is computed by averaging the two individual sample variances. The assumptions for the two-sample pooled t-test for the difference in two means are that there are random samples from two independent normal populations with common but unknown variance.
It is for this reason that a distribution curve represents the frequency of values, not the y-value attached to an x-value. t-test introduction. A two-sample t-test is an inferential test that determines if there is a significant difference between the means of two data sets. In other words, this t-test decides if the two data sets come from the same population (Figure 2A) or from different populations (Figure 2B).