Answer:
40.5 points
Step-by-step explanation:
To start off, I would set up a proportion. You're trying to find how many points out of the total 45 would give you a 90%.
90% as a fraction would be [tex]\frac{90}{100}[/tex].
When you set the two equal to one another, you get this:
[tex]\frac{x}{45} = \frac{90}{100}[/tex]
The bottom numbers are the total amount of points, and the top is how many points a student got.
To solve for x, which is the number of points a student would need to earn, you can cross multiply.
After you do that, you should get:
100x = 4050
To isolate x, you can divide by 100 on both sides.
x = [tex]\frac{4050}{100}[/tex] = 40.5 points
To check your answer, all you have to do is divide.
40.5 ÷ 45 = 0.9
0.9 as a percent is 90%.
