Answer
$$63.7{\text{m}}$$
Work Step by Step
$$\eqalign{
& {\text{Let }}C = {\text{74}}.{\text{2}}^\circ ,c = {\text{96}}.{\text{3 m}},B = {\text{39}}.{\text{5}}^\circ . \cr
& \cr
& {\text{Find }}b,{\text{ use the law of sines}} \cr
& \frac{b}{{\sin B}} = \frac{c}{{\sin C}} \cr
& b = \frac{{c\sin B}}{{\sin C}} \cr
& \cr
& {\text{Substitute}} \cr
& b = \frac{{\left( {{\text{96}}.{\text{3 m}}} \right)\sin \left( {{\text{39}}.{\text{5}}^\circ } \right)}}{{\sin \left( {{\text{74}}.{\text{2}}^\circ } \right)}} \cr
& {\text{Use a calculator}} \cr
& b = 63.7{\text{m}} \cr} $$
