Let the variance of first $\mathrm{n}$ natural numbers is ${\mathrm{\sigma }}^2$ then the variance of first $\mathrm{n}$ integral multiple of $4$ is $16{\mathrm{\sigma }}^2$
and the variance of first $\mathrm{n}$ odd natural numbers is $4{\mathrm{\sigma }}^2$
Then, the required ratio is $\frac{16{\mathrm{\sigma }}^2}{4{\mathrm{\sigma }}^2}=4$