Question

A student's grade depends on her score on four equally-weighted exams. Her average on the first three exams is 92. What must she score on the fourth exam in order to guarantee a final average of at least 90?

Answer 1

3x92 = 276 (first 3 exams)
average of at least 90 (90 x 4 = 360)

360 - 276 = 84

Answer
she needs to score at least 84 on the fourth exam in order to guarantee a final average of at least 90