On his first 2 tests Nate's average score was 80%. On his next 3 tests Nate's average score was 90%. What was his average score for all five tests?

Question

whpalmer4 · Answer

if the average score on the first two tests was 80%, we can just say that in effect, he got 80% on each test, right?  Similarly, for the next 3 tests, if the average was 90%, we can say he got 90% on each of those three tests.  Therefore, his total average for the 5 tests (assuming they are equally weighted) is just the average of 80, 80, 90, 90, 90

anonymous · Answer

Oh and then i just find the average and thats all?

whpalmer4 · Answer

Yes!  Easy, right?

anonymous · Answer

Haha yeah totally! Thank You!

whpalmer4 · Answer

It would be trickier if the different tests were worth different amounts of the grade.

whpalmer4 · Answer

The key to this problem is just realizing that if you have a set of data which has a given mean, you could replace that data (for the purposes of finding another mean, at least) with the same number of elements, all being exactly the mean.  Once you realize that, you're golden.

anonymous · Answer

Yeah so true! Its weird. I had no idea haha but it was all from your help. Thanks