### 20.5.1 General

Given a random variable X, you may want to know whether some effective parameter p is the same as some expected value p0. You will then want to test the hypothesis p=p0, which will be the null hypothesis H0. The alternative hypothesis will be H1. The tests are:

Two-tailed test
  — This test will reject the hypothesis H0 if the relevant statistic is outside of a determined interval. This is denoted by ’!=’.
Left-tailed test
  — This test will reject the hypothesis H0 if the relevant statistic is less than a specific value. This is denoted by ’<’.
Right-tailed test
  — This test will reject the hypothesis H0 if the relevant statistic is greater than a specific value. This is denoted by ’>’.