Question

A student scored 98 and 87 on his first two quizzes. Use a compound inequality to find the possible values for a third quiz score that would give him an average between 90 and 95 inclusive

Answer 1

90≤(98+87+s)/3≤95  multiply each expression by 3

270≤98+87+s≤285  combine like terms in center expression

270≤185+s≤285  subtract 185 from each expression

85≤s≤100

So the student can score from 85 through 100 to average from 90 to 95