Chapter 6.2, Problem 1QCE

A solid $S$ extends along the $x\text{-axis}$ from $x=1$ to $x=3$ . For $x$ between $1$ and $3$ , the cross-sectional area of $S$ perpendicular to the $x\text{-axis}$ is $3x^2$ . An integral expression for the volume of $S$ is $\text{\_\_\_\_\_\_\_\_}$ . The value of this integral is $\text{\_\_\_\_\_\_\_\_}$ .