Solve the problem.
-On the first four exams, your grades are 79, 98, 59, and 80. You are hoping to earn a C in the course. This will occur if the average of your five exam grades is greater than or equal to 70 and less than 80. What
Range of grades on the fifth exam will result in earning a C?
A)[34, 84)
B)(34, 84]
C)[24, 74)
D)(24, 74]

Question

Quizplus · Accepted Answer

To earn a C, the average of the five exams must be between 70 and 80. The sum of the first four grades is 79 + 98 + 59 + 80 = 316. For the average to be at least 70, the total of all five exams must be at least 5 * 70 = 350. Thus, the fifth exam must be at least 350 - 316 = 34. For the average to be below 80, the total must be less than 5 * 80 = 400. Therefore, the fifth exam must be less than 400 - 316 = 84. Hence, the range of grades on the fifth exam that results in earning a C is [34, 84).

Solve the Problem. -On the First Four Exams, Your Grades Are 79, 98