On your first four science tests, you score 82, 76, 88, and 84. What score must you get on the fifth test to get a mean score of 80?

Question

I dont really know how to find the mean, and mostly if you need to add something to find a mean

Answer 1

If your goal is 5 tests with an average score of 80, that must mean you must score a total of 5 x 80 points, or 400 points.

Since you already scored 82 + 76 + 88 + 84 = 330 points to date on the first four tests, you must score 400 minus 330 points = 70 points on the last test to achieve your goal.