We have the volume, length, and height, so we just need to plug it in to find the width. 256.5 = 4.5*w*6. Calculate this, and it'll become 256.5 = 27w. Then we divide both sides by 27 to find w. 256.5/27 = 27w/27. 9.5 = w. Width is 9.5 feet.
If the widow gets 0.125 and the son gets 0.4, together they get 0.525, or 52.5%. If you multiply 4000.4 * 0.525, you get 2100.21, which is a little over half of 4000.