Answer:

If we increase the income by 1% that means that the new income would be 1.01 the before one and if we replace this we got:

And the net increase can be founded like this:
![Test score_f -Tet score_i = 557.8 +36.7842 Income- [557.8 +36.42 Income] = 36.7842 Income -36.42 Income = 0.3642](https://tex.z-dn.net/?f=%20Test%20score_f%20-Tet%20score_i%20%3D%20557.8%20%2B36.7842%20Income-%20%5B557.8%20%2B36.42%20Income%5D%20%3D%2036.7842%20Income%20-36.42%20Income%20%3D%200.3642)
So then the net increase would be:
C. 0.36 points
Step-by-step explanation:
For this case we have the following linear relationship obtained from least squares between test scores and the student-teacher ratio:

If we increase the income by 1% that means that the new income would be 1.01 the before one and if we replace this we got:

And the net increase can be founded like this:
![Test score_f -Tet score_i = 557.8 +36.7842 Income- [557.8 +36.42 Income] = 36.7842 Income -36.42 Income = 0.3642](https://tex.z-dn.net/?f=%20Test%20score_f%20-Tet%20score_i%20%3D%20557.8%20%2B36.7842%20Income-%20%5B557.8%20%2B36.42%20Income%5D%20%3D%2036.7842%20Income%20-36.42%20Income%20%3D%200.3642)
So then the net increase would be:
C. 0.36 points