What is the change in the orbit radius when the electron in the hydrogen atom (Bohr model) undergoes the first Paschen transition ?

$\begin{array}{l}{\mathrm{r}}_{\mathrm{n}}=0.529\times \frac{{\mathrm{n}}^2}{\mathrm{Z}}{\text{\hspace{0.17em}A}}^{\mathrm{o}}\\ {\mathrm{r}}_4-{\mathrm{r}}_3=0.529\times \frac{16}{1}-0.529\times \frac{9}{1}{\text{A}}^{\mathrm{o}}\\ =0.529(16-9){\text{A}}^{\mathrm{o}}\\ =0.529\times {10}^{-10}\left[16-9\right]\mathrm{m}\\ =7\times 0.529\times {10}^{-10}\\ =3.7\times {10}^{-10}\mathrm{m}\end{array}$