Model and hypotheses
In both examples in the first page of this section, there was knowledge of the population standard deviation σ (at least when H0 was true). This greatly simplifies the problem of finding a p-value for the test.
In the following examples, the population standard deviation, σ, can be treated as a known value.
In both examples, the hypotheses were of the form,
H0 : μ = μ0
HA : μ ≠ μ0
Summary Statistic and p-value
We now explain how the p-value for testing a population mean can be obtained when σ is a known value.