Answer
Accepting a null hypothesis means that the null hypothesis is true.
Not rejecting a null hypothesis means that we can not affirm that the null hypothesis is false.
Work Step by Step
Remember the example in section 10.1 in which the null hypothesis is that "the defendant is innocent".
If we accept the null hypothesis, we are affirming that the defendant is innocent. But, if we do not reject the null hypothesis, we are saying that there is not enough evidence to conclude that the defendant is guilty.
