## College Algebra (10th Edition)

Average = Sum of items $\div$ Number of items Required average = 80 As the last test counts as 2 exams, let the score be "2x"; one "x" per test score. = $\frac{80 + 83 + 71 + 61 + 95 + x + x}{7} = 80$ = 390 + 2x = 560 2x = 560 - 390 2x = 170 x = 85 Score needed = 85