A student scored 84, 78, and 86 on 100-point examinations. How many points does he or she need to score on a 200-point final examination to get an average of 90%, which is an A, in the course?
The student would have to score 202 points on the 200 point final.
After the 200 point final plus 3 x 100 point tests there are 500 total points.
90% of 500 points = 450 points required for an A.
Add the three previous scores 84 + 86 + 78 = 248 points.
To find the points needed for an A subtract 248 from 450.
450- 248 = 202
It is impossible for the student to get an A. there are only 200 points possible and the student needs 202 points.