Question

Alan has scored 99, 85, and 74 on his previous three tests. What score does he need on his next test so that his average (mean) is 83?

Answer 1

(99+85+74+x)/4=83
multiply both by 4
99+85+74+x= 332
258+x=332
subtract 258 both sides
x= 74

He must get a 74.

To check answer:
99+85+74+74= 332
332/4 = 83

It’s right!

Hope it helps