Question

Stephen earned scores of 88 points, 94 points. 89 points, and 85 points on four tests.

Answer 1

answer

94

set up equations

average = total points / number of tests

total points = test1 + test2 + test3 + test4+ test5

total points = 88 + 94 +89 + 85 + test5

total points = 356 + test5

plug total points into first eqation and rearrange

average = total points / number of tests

average = (356 + test5)/number of tests

average * number of tests = 356 + test5

test5 = average * number of tests - 356

plug in values for average and number of tests

test5 = average * number of tests - 356

test5 = 90 * 5 - 356

test5 = 94