They refer to the learning cone a.k.a. the learning pyramid. That model needs to die.<p>See <a href="https://www.worklearning.com/2006/05/01/people_remember/" rel="nofollow">https://www.worklearning.com/2006/05/01/people_remember/</a>
There are several classes online for statistics.<p><a href="https://github.com/melling/MathAndScienceNotes/blob/master/statistics/README.md" rel="nofollow">https://github.com/melling/MathAndScienceNotes/blob/master/s...</a>