Among ${\left[{\mathrm{I}}_3\right]}^{+},{\left[{\mathrm{SiO}}_4\right]}^{4-},{\mathrm{SO}}_2{\mathrm{Cl}}_2,{\mathrm{XeF}}_2,{\mathrm{SF}}_4,{\mathrm{ClF}}_3,\mathrm{Ni}{\left(\mathrm{CO}\right)}_4,{\mathrm{XeO}}_2{\mathrm{F}}_2,{\left[{\mathrm{PtCl}}_4\right]}^{2-},{\mathrm{XeF}}_4$, and ${\mathrm{SOCl}}_2$, the total number of species having ${\mathrm{sp}}^3$ hybridised central atom is

${\mathrm{I}}^{3+}$ ion has ${\mathrm{sp}}^3$ hybridisation and bent shape containing two bond pairs and two lone pairs. Structure of ${{\mathrm{SiO}}_4}^{4-}$ is tetrahedral structure and $\mathrm{Si}$ is ${\mathrm{sp}}^3$ hybridised. The molecular geometry of ${\mathrm{SOCl}}_2$ is trigonal pyramidal and its electron geometry is tetrahedral. In this molecule sulphur undergo ${\mathrm{sp}}^3$ hbridisation,

${\mathrm{XeF}}_2$ molecule is linear molecule but it is ${\mathrm{sp}}^3\mathrm{d}$ hybridised. In ${\mathrm{SF}}_4$, sulphur undergo ${\mathrm{sp}}^3\mathrm{d}$ hybridisation and molecule has see-saw shape. In  ${\mathrm{ClF}}_3$, chlorine undergo ${\mathrm{sp}}^3\mathrm{d}$ hybridisation and shape of the molecule is T-shape.

The nickel tetracarbonyl is a tetrahedral complex in which nickel metal undergo ${\mathrm{sp}}^3$ hybridisation. In the molecule ${\mathrm{XeO}}_2{\mathrm{F}}_2$, $\mathrm{Xe}$ undergo ${\mathrm{sp}}^3\mathrm{d}$ hybridisation and molecular shape is see-saw. Tetrachloroplatinate(II) is a square planar complex in which platinum undergoes ${\mathrm{dsp}}^2$ hbridisation.

${\mathrm{XeF}}_4$ is square planar compound in which xenon undergoes ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridisation. In the tetrahedral molecule ${\mathrm{SO}}_2{\mathrm{Cl}}_2$, sulphur undergoes ${\mathrm{sp}}^3$ hybridisation.

Hence, the total number of ${\mathrm{sp}}^3$ hybridised central atom molecules are 5.