Respuesta :

450 / (3/8) = x / 1....450 ft to 3/8 hr = x ft to 1 hr
cross multiply because this is a proportion
(3/8)(x) = (450)(1)
3/8x = 450
x = 450 * 8/3
x = 3600/3 reduces to 1200

so the conveyor belt moves at the unit rate of 1200 ft per hr