The null hypothesis is a statement of equality to be tested. The alternative hypothesis is a statement of inequality that is the complement of the null hypothesis.
There are two parts to a hypothesis test — the null hypothesis and the alternative hypothesis.
The null hypothesis H_0 is a statement of equality to be tested.
The alternative hypothesis H_a is a statement of inequality that is the complement of the null hypothesis.
A claim can be part of the null or alternative hypothesis. With the above facts in mind, let's consider the given statement.
Tom drinks at least eight glasses of water every day.
Notice that Tom's claim is a statement of inequality. Therefore, we can relate the claim with the alternative hypothesis. Consequently, the null hypothesis is the complement.
Null Hypothesis
Alternative Hypothesis
The mean is greater than 8 glasses H_0:μ > 8
The mean is less than or equal to 8 glasses (claim) H_a:μ ≤ 8
