#### Answer

Therefore, the density in lb/in^3 is 0.773124 $\frac{lb}{in^{3}}$.

#### Work Step by Step

Using the formula $Density=\frac{Mass}{Volume}$ and the conversion factors shown in the formula, the density can be calculated in g/cm^3.
$Density = \frac{21.4 g}{cm^{3}}\times\frac{1 lb}{453.592 grams}\times\frac{1 cm^{3}}{0.0610237 in^{3}} = 0.773124 \frac{lb}{in^{3}}$.