How To Analyze Data Using the Average
betterexplained.com
betterexplained.com
Bonus for harmonic mean.
School would be so much easier and interesting if the subjects were organized better.
I think the bad organization is a consequence of school performance being measured by tests. It is much easier and quicker to merely memorize the formula and regurgitate than to really understand what is going on. Then the people who learned by parroting become teachers and are even less able to explain the crucial principles; resulting in a vicious cycle.
It surprsies me how often "cram and forget" is the operating mode for education (I had my share of that). Yep, I think measuring performace with tests is a big part of it.
You hit the nail on the head about student interest as well. Many people end up hating math because it is often taught in that rote, formulaic manner.
If you had 1kg weights at distances 2 3 and 10 (sum of 15), you should put the fulcrum of a lever at 5 to keep the set balanced. (Torque on right: 10 - 5 = 5. Torque on left: 5 - 2 = 3, and 5 - 3 = 2, for a total of 5).
Different sized masses? You literally take the weighted average :).