Jack scored 90, 92, 94 and 96 on his first four tests. What is the minimum score he would need to earn on his next test to score an average of 94?

The average is calculated by adding the scores up and then dividing by the number of scores.

(90 + 92 + 94 + 96 + x) / 5 = 94 (where x is the score he needs)

(372 + x) / 5 = 94

multiply both sides by 5.

372 + x = 470

subtract 372 from both sides.

x = 98