Question

Rueben has scored 81 , 89 , 90 , 83 , and 77 on his previous five tests. what score does he need on his next test so that his average (mean) is 82 ?

Answer 1

Let x = the next score

If (81 + 89 + 90 + 83 + 77 + x) ÷ 6 = 82

⇒ 420 + x = (82 × 6)

⇒ x = 492 - 420

x = 72

Thus to get an 82 average he need to get 72 on his next test.