SOLUTION: A student has taken 3 tests and earned an 85, 80, and 75. She will take one more test comprised of 20 questions. Each question is worth 5 points. The student would like to have a t

Algebra ->  Average -> SOLUTION: A student has taken 3 tests and earned an 85, 80, and 75. She will take one more test comprised of 20 questions. Each question is worth 5 points. The student would like to have a t      Log On


   

Question 1081412: A student has taken 3 tests and earned an 85, 80, and 75. She will take one more test comprised of 20 questions. Each question is worth 5 points. The student would like to have a test average of at least 87. What grades on the 4th test will give her this average? I'm not sure if I should solve this using an inequality equation or not. I've tried to make one, but it didn't work.
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
find the mean (mean is the same as average):
(85+80+75+x)/4 => 87
(240+x)/4 => 87
240+x => 348
x => 108
The student is going to have a tough time getting a test average of 87!