SOLUTION: Martin’s average (arithmetic mean) score after 4 tests is 89. What score on the 5th test would bring Martin’s average up to exactly 90? (A) 90 (B) 91 (C) 92 (D) 93 (E) 94

Algebra ->  Average -> SOLUTION: Martin’s average (arithmetic mean) score after 4 tests is 89. What score on the 5th test would bring Martin’s average up to exactly 90? (A) 90 (B) 91 (C) 92 (D) 93 (E) 94       Log On


   

Question 324916: Martin’s average (arithmetic mean) score after 4 tests is 89. What score on the 5th test would bring Martin’s average up to exactly 90?
(A) 90 (B) 91 (C) 92 (D) 93 (E) 94


Found 2 solutions by vleith, JBarnum:
Answer by vleith(2983) About Me  (Show Source):
Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
since the average is 89 we really dont need to know what the 4 tests scores are sin 4 89's would have the same average
%2889%2B89%2B89%2B89%2Bx%29%2F5=90 multiply by 5
%2889%2B89%2B89%2B89%2Bx%29=450 add the 89s
%28356%2Bx%29=450 subtract 356
x=94
E