Question
your test scores in one class are 80 and 88. what possible scores can you earn on your next test to have a test average between 84 and 89, inclusive?
Answers
Damon
well, try 84
(80 + 88 + x)/3 = 84
168/3 + x/3 = 84
168 + x = 252
x = 84 of course since that was original average
now 89
80 + 88 + x = 3*89 = 267
168 + x = 267
x = 99
so
84 </= x </= 99
(80 + 88 + x)/3 = 84
168/3 + x/3 = 84
168 + x = 252
x = 84 of course since that was original average
now 89
80 + 88 + x = 3*89 = 267
168 + x = 267
x = 99
so
84 </= x </= 99