Given:
For a 30-hour review course, the average score is 620.
For a 70-hour review course, the average score is 795.
To find: The linear equation and the average score for 54 hours review course.
Step-by-step explanation:
Let us take two points
![(30,620)\text{ and }(70,795)](https://img.qammunity.org/2023/formulas/mathematics/college/tavx2yts8zr25cqx1osvvfix2he80y517g.png)
Using the two-point formula,
![(y-y_1)/(y_2-y_1)=(x-x_1)/(x_2-x_1)](https://img.qammunity.org/2023/formulas/mathematics/college/y3htm86mupzj3pmgn31maj2nuw5l95fen7.png)
On substitution we get,
![\begin{gathered} (y-620)/(795-620)=(x-30)/(70-30) \\ (y-620)/(175)=(x-30)/(40) \\ 40y-24800=175x-5250 \\ 40y=175x-5250+24800 \\ 40y=175x+19550 \\ y=(35)/(8)x+(1955)/(4) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fhodjrz7jennfgs3nv2938cdsjpog0i12j.png)
Thus, the linear equation is,
![y=(35)/(8)x+(1955)/(4)](https://img.qammunity.org/2023/formulas/mathematics/college/l52d42gmvjeqnrshrusdqgkh1zynzyzksi.png)
Therefore, for a 54-hour review course
The average score is,
![\begin{gathered} y=(35)/(8)(54)+(1955)/(4) \\ y=725 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/x3h53l58rnwzn16lfexuromwz4p7m960ce.png)
Thus, the average score for a 54-hour review course is 725.