SOLUTION: Four test scores are 70, 84, 65, and 92. What must you earn on the fifth test in order to get the average of 80.

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Question 1010562: Four test scores are 70, 84, 65, and 92. What must you earn on the fifth test in order to get the average of 80.
Answer by 0309083(1) About Me  (Show Source):
You can put this solution on YOUR website!
You have 5 test trying to get an average of 80, so multiply the 5 test you are taking times the average to see the sum of all your grades, 80*5= 400, now subtract the ones you know, 400-89-84-65-92-70, and you get 89, you can check this by adding up all your known grades plus 89 and dividing it by the grades getting an average of 80, 89+84+65+92+70+89= 400/5= 80.