The average

Question

what is the minimum sore that lacey needs to make up on a fourth test so that when it is averaged with three tests (68, 79 and 72) the average will be greater than 75

Answer 1

Since the average needs to be greater than 75, we write an inequality.  This value will get you the minimum score he needs.

 

 

(68 + 72 + 79 + x) / 4 > 75

 

 

where x is the score he needs.

 

 

(219 + x) / 4 > 75

 

219 + x > 300

 

x > 81

 

The score he needs is 82.