To find height $ h $ use formula:
$$ V = \dfrac{ r ^{ 2 } \cdot h \cdot \pi}{ 3 } $$After substituting $ V = 615.44 $ and $ r = 7 $ we have:
$$ 615.44 = \dfrac{ 7 ^{ 2 } \cdot h \cdot \pi}{ 3 } $$$$ 615.44 \cdot 3 = 7 ^{ 2 } \cdot h \cdot \pi $$$$ 1846.32 = 49 \cdot h \cdot \pi $$$$ h = \dfrac{ 1846.32 }{ 49 \, \pi} $$$$ h = 11.9939 $$