Answer
$19\;ft^3$.
Work Step by Step
The given measurements are
Width $w=3.0\;ft$.
Length $l=4.2\;ft$.
Depth $d=1.5\;ft$.
Volume $V=w\times l\times d$
Substitute all the values.
$V=3.0\;ft\times 4.2\;ft\times 1.5\;ft$
Simplify.
$V=18.9\;ft^3$
Rounded value.
$V=19\;ft^3$.
