Variable weights

Let's say you expect students' term 1 grades to be better predictors of their final grades. To test this hypothesis, you would expect that their predicted grades would get closer to their actual grades if you increase the weight on their term 1 grades.

However, because it's not clear how changing the weights in the average will affect the outcome, you'll set up a formula to make it easier to adjust weights on the fly to test your hypothesis. This will allow you to see how tweaking your weighted averages will change the accuracy of your predictions.