Answer:
78%
Explanation:
Ok to solve this we can write this as
80 =
We put the equation like this because were finding out how much he needs to get on his 5th test x in order to get a 80%
Your grade is the average of all of your scores hence the divided by 5
We next multiply both sides of the equation by 5 to get
400 = 72+82+85+83+x
400= 322+ x
78 = x
He must get a 78% minimum on his next test to get 80%
Hope that helps!