Patrick David has a great article on hypothesis testing, p-hacking, and multiple comparison bias:
The most important part of hypothesis testing is being clear what question we are trying to answer. In our case we are asking:
“Could the most extreme value happen by chance?”
The most extreme value we define as the greatest absolute AMVR deviation from the mean. This question forms our null hypothesis.
Give this one a careful read and try out the code. This is an important topic for anyone who analyzes data to understand.