A statistical hypothesis is a statement about a parameter of a probability distribution. Through the sample elements a test is made that will indicate the acceptance or rejection of the formulated hypothesis.

Statistical hypothesis is an assumption of a population parameter. For example:

1. The average income of the population of Forquilhinha is $ 350.00. So H: μ = 350.00.

2. The proportion of students failing is 35%, ie: H:*P* = 0,35

The counterpart to an alternative hypothesis (H_{1}) is the null hypothesis (H_{0}). The first is always expressed by an inequality and the second always by an equality.