In order to get an average of 90, the student needs to get a score of 96.
The average can be found by summing up all the numbers in a data set and then dividing it by the number of characters in that dataset.
Assuming the average is 90, and that the score the student needs to get is x, the formula would be:
<em>Average = Sum of scores / Number of scores </em>
90 = (83 + 89 + 92 + x) / 4
90 x 4 = 264 + x
x = 360 - 264
x = 96
The student needs to get a score of 96 on the last exam.
<em>Find out more at brainly.com/question/13406591.</em>