Question

Yoko has scored 81 , 84 , 84 , 69 , and 76 on her previous five tests. What score does she need on her next test so that her average (mean) is 81 ?

Answer 1

Took must make a 92 on the next test.
(81+84+84+69+76+x)/6=81
(394+x)/6=81
Multiply by 6 on both sides
394 + x = 486
Subtract 394 from both sides.
x= 92