Theresa earned scores of 88 points, 84 points, 88 points, and 91 points on four tests. what is the lowest score she can get on the fifth test and still finish with an average score of 90 points?

Let x represent her score on the next test. 88, 84, 88, 91, and x are 5 scores Take the sum of those numbers and divide by 5 Set that expression equal to 90. Solve for x to find the lowest score she can make and have an average of 90.