Question

John got a 76, 68, and 83 on his first three test. What score does he need on his fourth test to achieve an 80 average?

Answer 1

It's 93.
simple calculate it by:
(76+68+83+x)/4=80
then 73*5-(67+75+73+69)=x
where x here is the grade needed to reach an av. of 80. 4 is the number of tests.
*common answer*