AREAS AND VOLUMES OF SIMILAR SOLIDS URGENT?

Two similar prisms have proportional dimensions. Find the ratio between lengths of these prisms:
[tex] k=\dfrac{7}{5} [/tex].
The ratio between volumes of similar prisms is
[tex] \dfrac{V_{large}}{V_{small}}=k^3 [/tex].
If volume of small prism is 50 cub. m, then
[tex] \dfrac{V_{large}}{50}=(\dfrac{7}{5} )^3=\dfrac{343}{125},\\V_{large}=\dfrac{343\cdot 50}{125} =137.2 [/tex]cub. m.
Answer: 137.2 cub. m.