Chapter 5.6, Problem 7E

Builder’s old measurement was instituted by law in England in1773 as the way to estimate the total tonnage $T$ of a wooden ship from its beam width $W$ and its length $L$, both measured in feet. The formula is

$T=\frac{\left(L-0.6W\right)W^2}{188}$

In this Exercise, we consider wooden ships of length 120 feet.

a. What tonnage is given by the Builder’s Old Measurement for a ship of beam width 25 feet?

b. What beam width will give a tonnage of 400?