Question

Carlos has scored 83, 81, and 73 on his previous three tests. What score does he need on his next test so that his average (mean) is 83 ?

Answer 1

95

Explanation:

let x be his mark in the fourth test, then

mean =
`(83+81+73+x)/(4)` = 83 ( multiply both sides by 4 )

83 + 81 + 73 + x = 332

237 + x = 332 ( subtract 237 from both sides )

x = 95