$15\mathrm{.}20$ Compute the maximum deflection of a $10-$in$.-$by$-14-$in$.$ simply supported solid rectangular redwood $($S$4$S$)$ beam. The span length is $15ft$ and the beam is subjected to a uniformly distributed load of $1000l\frac{b}{f}t.$ The allowable deflection is $\frac{1}{300}$ of the span length. Using the moment$-$area method, check$/$find the deflection