My Daughter's Test Scores
My daughter was interested in how her test scores are calculated. And I sort of lied and gave her a more useful, yet advanced example. Here is what I told her.
Lets say you have 5 tests, and you got 60 70 80 90 and 100 on them, all out of 100. You have a total of 400 points, but the maximum you could get is 500 points, or 400/500. This means that your average, is 80%.
Now, your Professor was very generous, and is dropping your lowest grade. You now only have 4 graded tests, so the maximum is 400, and your test scores are 70 80 90 and 100. You now have 340 points out of 400 points. If we scale this up, it becomes 425/500, which is 85%
So, dropping your 60 point test drops the total points you could get from 500 to 400, and the points you got only drops 60. Because this is your lowest score, more complicated math basically dictates that there is no way the average can go in any direction but up. In this case, it raises your total percent by 5%, which can be significant.