Recall that, to compute the average we can use the following formula:
[tex]A=\frac{x_1+\cdots+x_n}{n}\text{.}[/tex]
Let x be the third score that Jim needs to average 71 points, then we can set the following inequality:
[tex]\frac{65+69+x}{3}\ge71.[/tex]
Multiplying the above inequality by 3, we get:
[tex]65+69+x\ge213.[/tex]
Subtracting 65 and 69 we get:
[tex]\begin{gathered} x\ge213-65-69, \\ x\ge79. \end{gathered}[/tex]
Therefore, to average more than 71 Jim has to score at least 79 points in his last test.
Answer:
[tex]79.[/tex]