+273 A class of 30 students recently took a test. If 20 students scored 80, 8 students scored 90, and 2 students scored 100, then what was the class average (the mean) on this test?
A class of 30 students recently took a test. If 20 students scored 80, 8 students scored 90, and 2 students scored 100, then what was the class average (the mean) on this test?
Add up all the scores then divide that total by the number of students.
20 students made 80 so the total of those 20 is 20 • 80 = 1600
8 students made 90 so the total of those 8 is 8 • 90 = 720
2 students made 100 so the total of those 2 is 2 • 100 = 200
Add up all the scores 1600 + 720 + 200 = 2520
Divide that by 30 2520/30 = 84 is their average
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