Correct. Find the volume of the cylinder and then subtract the volume of two hemispheres, or one sphere.

Volume of cylinder: $\displaystyle\pi{{r}}^{{2}}{h}=\pi\cdot{{21}}^{{2}}\cdot{100}\approx\frac{{22}}{{7}}\cdot{441}\cdot{100}={138},{600}\usepackage{cmbright}\Huge\$

Volume of sphere: $\displaystyle\frac{{4}}{{3}}\pi{{r}}^{{3}}=\frac{{4}}{{3}}\pi\cdot{{21}}^{{3}}\approx\frac{{4}}{{3}}\cdot\frac{{22}}{{7}}\cdot{9261}={38},{808}\usepackage{cmbright}\Huge\$

Volume of the solid: $\displaystyle{138},{600}-{38},{808}={99},{792}\approx{99},{800}\usepackage{cmbright}\Huge\$