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.
Overview of T-tests. Essentially, a t-test is used to compare two samples to determine if they came from the same population. Whenever we draw a sample from the population, we can reasonably expect that the sample mean will deviate from the population mean a little bit.