Sarah Was trying to figure out her grades for her math course. She only knew the grade of 4 of the tests total she scored a 94, 67, 83, and 93 . If sarah ended up with a grade of 90 , what did she get on the 5th and Final test
+128570 Let x be the unknown test grade.....so we have
[ 94 + 67 + 83 + 93 + x ] / 5 = 90 multiply both sides by 5 and simplify
337 + x = 450 subtract 337 from both sides
x = 113
[90 X 5] - [ 94+ 67+ 83+ 93]=113??????!!!!!!!!!
I think there is something wrong with your numbers?.
To do this, you must use the formula for mean backwards.
Add all values together and divide by # of values.
so it would be
94+67+83+93+n
_____________ = 90
5
now simplify!!!!!
multiply both sides by 5 so now you have
94+67+83+93+n = 450
simplify again
337+n=450
n=113
thats your answer... iguess she got extra credit for a score of 113
