Question 1140301
there are 5 equally weighted test.
for the student to get an average of 90, the total has to be equal to 5 * 90 = 450.


that's because a total score of 450 / 9 equals an equally weighed average of 90.


the 4 scores that the student has so far adds up to 356.


subtract that from 450 to get 450 - 356 = 94.


that's the score the student needs to get on the fifth test.


if the student gets a score of 94 on the last test, then the sum of all 5 scores will be 356 + 94 = 450 and the average will be 450 / 5 = 90.