Question

abdul has scored 73, 86, 71, 66, and 63 on his previous five tests. what score does he need on his next test so that his average (mean) is 72?

Explanation:

Step1: Find the sum of the first five - test scores

$73 + 86+71 + 66+63=359$

Step2: Let the score on the sixth test be $x$. Set up the average formula.

The average of six scores is $\frac{359 + x}{6}$, and we want this average to be 72. So, $\frac{359 + x}{6}=72$.

Step3: Solve the equation for $x$.

Multiply both sides of the equation by 6: $359 + x=72\times6$.
$72\times6 = 432$, so $359+x = 432$.
Subtract 359 from both sides: $x=432 - 359$.
$x = 73$.

Answer:

73