Expert: Lynn Houston - 5/15/2009

Question
Am rusty in math and need to figure out the following.  If i have a class where grades are assigned on a percentage basis.  There are five quizzes which have a total possible of 90 points and this account for 30% of the course grade.  There are two major tests that account for a total of 120 points and are worth 70% of the total course grade.  How do I solve this equation and determine the percentage each student has achieved?  The total points available for all work is 210.  Can this be done and if not what needs to change in the problem?

Answer
You would determine the grade (percentage) for quizzes and the grade for tests and then multiply the quiz score by .3 and the test score by .7 and add them together.  So, lets say someone got 17, 16, 18, 14 and 12 on quizzes and 78 and 85 on tests.

17 +16+18+14+12/5(18) = 85.5%
54+45/2(60) = 82.5%

Their grade would be .855(.3) + .825(.7) = 83.4%

18 and 60 are assuming that the quizzes and test are each of equal value to each other.  If they're not, then you just need to determine the grade on each test and then average to get the quiz score and the test score, then multiply by your weights.