9.1 Null and alternate hypotheses

The actual test begins by considering two hypotheses . They are called the null hypothesis and the alternate hypothesis . These hypotheses contain opposing viewpoints.

$H_o$ : The null hypothesis: It is a statement about the population that will be assumed to be true unless it can be shown to be incorrect beyond a reasonable doubt.

$H_a$ : The alternate hypothesis: It is a claim about the population that is contradictory to $H_o$ and what we conclude when we reject $H_o$ .

Since the null and alternate hypotheses are contradictory, you must examine evidence to decide if you have enough evidence to reject the null hypothesis or not. The evidence is in the form of sample data.

After you have determined which hypothesis the sample supports, you make a decision. There are two options for a decision. They are "reject $H_o$ " if the sample information favors the alternate hypothesis or "do not reject $H_o$ " or "fail to reject $H_o$ " if the sample information is insufficient to reject the null hypothesis.

Mathematical Symbols Used in $H_o$ and $H_a$ :

Optional collaborative classroom activity

Bring to class a newspaper, some news magazines, and some Internet articles . In groups, find articles from which your group can write a null and alternate hypotheses. Discuss yourhypotheses with the rest of the class.