The maximum safe load for a horizontal rectangular beam varies jointly with the width (in.) of the beam and the square of the thickness (in.) of the...

The maximum safe load for a horizontal rectangular beam varies jointly with the width (in.) of the beam and the square of the thickness (in.) of the beam and inversely with its length (ft). If an 8-foot beam will support up to 750 pounds when the beam is 4 inches wide and 2 inches thick, what is the maximum safe load in a similar beam 10 feet long, 6 inches wide, and 2 inches thick.