ABSTRACT
Two sample tests are represented by the graphical method. The two sample variables are control and treatment for the component insulin in mcU/ml. The scattered dots are marked on both parameters under the null hypothesis. As in the one-sample test, the authors need to draw a line indicating the null hypothesis. On the one-sample test, they are given the value. In a two-sample test, the people have to compute it. A one-tailed test starts with a slightly different null hypothesis: the drug has no effect on insulin blood levels or it decreases the average level of insulin in blood. Therefore, the alternative hypothesis is: the drug increases the levels of insulin in the blood. In standard statistical practice, it is often necessary to compute something called Confidence Intervals or CIs. One common way to control for unwanted variation is to perform paired-sample tests.
