Write a proportion to find how many points x a student needs to score on a test worth 50 points to get a test score of 40%. one proportion is

To get a 40% you must get 16 points. We know this because 5 is 10% of 50, right. Then 4 is 10% of 40.

Hello! I can help you with this! To write a proportion for this situation, you set it up like this: 

x/50 = 40/100.

We set the proportion up like this, because we are looking for the amount of points out of 50 needed to get a score of 40% on the test. Cross multiply the values diagonally in order to get 100x = 2,000. Now, divide each side by 100 to isolate the "x". 2,000/100 is 20. x = 20. A student needs to get 20 points out of 50 points in order to get a score of 40%. The answer is 20.