Question

Jim has received scores of 65 and 69 on his first two 100 point tests.What score must he get on his third 100 point test to keep an average of 71 or greater?Third test ≥ (If the average is greater then the possible number of points, enter DNE)Submit QuestionQuestion 3

Answer 1

Recall that, to compute the average we can use the following formula:

`A=(x_1+\cdots+x_n)/(n)\text{.}`

Let x be the third score that Jim needs to average 71 points, then we can set the following inequality:

`(65+69+x)/(3)\ge71.`

Multiplying the above inequality by 3, we get:

`65+69+x\ge213.`

Subtracting 65 and 69 we get:

`\begin{gathered} x\ge213-65-69, \\ x\ge79. \end{gathered}`

Therefore, to average more than 71 Jim has to score at least 79 points in his last test.

Answer:

`79.`