Correct. Find the volume of the hemisphere and then subtract the volume of the cone. Because $\displaystyle{d}={30}\usepackage{cmbright}\Huge\$ , $\displaystyle{r}={15}\usepackage{cmbright}\Huge\$ .

Volume of hemisphere: $\displaystyle\frac{{1}}{{2}}{\left(\frac{{4}}{{3}}\pi{{r}}^{{3}}\right)}=\frac{{4}}{{6}}\pi\cdot{{15}}^{{3}}=\frac{{4}}{{6}}\pi\cdot{3},{375}\approx\frac{{4}}{{6}}\cdot{3.14}\cdot{3},{375}={7},{065}\usepackage{cmbright}\Huge\$

Volume of cone: $\displaystyle\frac{{1}}{{3}}\pi{{r}}^{{2}}{h}=\frac{{1}}{{3}}\pi\cdot{{15}}^{{2}}{\left({9}\right)}\approx{3.14}\cdot{225}\cdot{3}={2},{119.5}\usepackage{cmbright}\Huge\$

Volume of the solid: $\displaystyle{7},{065}-{2},{119.5}={4},{945.5}\approx{4},{900}\usepackage{cmbright}\Huge\$