You have to be very careful how you set this up. For every girl (who counts as 1) there are 3 boys (who count as 3). The total number in the proportion is 3 + 1 =4. You are given a total, but that is both boys and girls. That's why you need the 4.
3/4 = x / 236 Cross multiply
4x = 3 * 236
4x = 708 Divide by 4
x = 708/4
x = 177
There are 177 boys at the school and 236 - 177 = 59 girls.
Let w and 2w-5 be the width and length, respectively, of the rectangle. Then: w(2w-5)=52 2w²-5w-52=0 (2w-13)(w+4)=0 w=13/2 or -4 The rectangle is 6.5 ft by 8 ft. ☺☺☺☺