Q. 22 Suppose a professor counts the final exam as being equal to each of the other tests in her course, and she will also change the lowest test score to match the final exam score if the final exam score is higher. If a student’s four test scores are 83, 67, 52, and 90, what is the lowest score the student can earn on the final exam and still obtain at least an 80 average for the course?
Sum of Scores including last score = 83 + 67 + x + 90 + x = 2x + 240
Equation will be
(2x + 240 ) / 5 = 80
2x + 240 = 400
2x = 400 – 240
2x = 160
X = 80
Student can earn a lowest score of 80 and to keep the average at 80.