its a word problem and I don’t understand

Question

you are taking a course that has four test. the first three tests are 100 points each and the fourth test is 200 points. to get an A in the course, you must have an average of at least 90% on the four test. your scores on the first three tests were 87, 92, and 84. what must you score on the fourth test to get an A for the course?

Answer 1

Assuming that the fourth test is NOT weighted.

You need at least 360 points (4 x 90)

You currently have 263 (87+92+84)

 

So how many do you need to get on the fourth test