Dave currently has an 85.5 average in his math class. If Dave earned an 86, a 93, an 84, and an 89 on the first four tests, what must he receive on the fifth test to make a 90 in the class?

Answer 1

You first need to take all 4 test scores and add them up which gives you 352. If you divide that by 4 (the number of tests taken) it gives you an 88.

Now you need to take that 352 from the 4 test scores and find a number to add to it so that when you divide it by 5 (there are now 5 tests) it would equal 90.

So after we plug in different numbers we figure out that 352 plus 98 is 450 and if we divide that by 5 we get 90. So Dave needs to get a 98 on his next test.