9.1 The Nature of Hypothesis Testing
Over the years, however, null hypothesis has come to mean simply a hypothesis to be tested.
Null Hypothesis:
H0: μ = μ0,
where μ0 is some number
Alternative Hypothesis:
two tailed 实例：
one tailed 实例：
评判标准：
Type I and Type II Errors：
Significance Level
所以需要balancing
In other that the data provide sufficient evidence to support the null hypothesis
即，reject or not reject 取决于是否满足备择假设，如果满足备择假设则reject；如果不满足备择假设则 not reject
fact with the phrase “the test results are not statistically significant at the α level.”