Jim has received scores of75and81on his first two 100 point tests.What score must he get on his third 100 point test to keep an average of84or greater?

Question

asked Jun 11, 2023 206k views

1 Answer

Przemek · Answer 1 · 2023-06-15T10:05:12+0000

start writing the corresponding equation using the corresponding formula for the average grade

$\begin{gathered} \bar{x}=(x_1+x_2+x_3)/(3) \\ \text{then, } \\ 84=(75+81+x_3)/(3) \\ 84=(156+x_3)/(3) \end{gathered}$

solve the equation

$\begin{gathered} 84\cdot3=156+x_3 \\ 252=156+x_3 \\ 252-156=x_3 \\ 96=x_3 \end{gathered}$

He must get at least 96 points on his test to keep an average of 84