To find radius $ r $ use formula:
$$ V = \dfrac{ h ^{ 2 } \cdot r \cdot \pi}{ 3 } $$After substituting $V = 3786\, \text{cm}$ and $h = 16\, \text{cm}$ we have:
$$ 3786\, \text{cm} = \dfrac{ 16\, \text{cm} ^{ 2 } \cdot r \cdot \pi}{ 3 } $$$$ 3786\, \text{cm} \cdot 3 = 16\, \text{cm} ^{ 2 } \cdot r \cdot \pi $$$$ 11358\, \text{cm} = 256\, \text{cm}^2 \cdot r \cdot \pi $$$$ r = \dfrac{ 11358\, \text{cm} }{ 256\, \text{cm}^2 \, \pi} $$$$ r = 14.1225\, \text{cm}^-1 $$