Hypothesis Testing | Population Mean: σ Known | Two-Tailed Test

The procedure for a two-tailed test differs from a one-tailed test (lower tail and upper tail). The first step, to calculate the test statistic, is the same. However, the p-value in a two-tailed test is the probability of getting a value for the test statistic as unlikely as or more unlikely than that provided by the sample. The rejection rule for the p-value is the same. Their are two critical values in a two-tailed test. The lower critical value is the value of the test statistic corresponding to an area of alpha / 2 in the lower tail. While the upper critical value is the value of the test statistic corresponding to an area of alpha / 2 in the upper tail.

0:00 - Introduction
1:30 - Test Statistic
3:05 - p-Value Approach
8:30 - Critical Value Approach