Question 589248
The ratio of the volmes of similar solids, is the cube of the ratio of its linear dimensions. In this case that ratio would be {{{4^3=64}}}.
If we did not know that, we would know that the volume of a pyramid with a height of 9 inches, and a sqare base of side length x inches is, in cubic inches,
{{{v=(1/3)x^2*9 =((1/3)*9)x^2  = 3x^2}}}
A larger pyramid, enlargerd by a factor of 4, would have a height of {{{4*9}}} inches, a base side length of {{{4x}}} inches, and a volume, incubic inches, of
{{{V=(1/3)(4x^2)(4*9) = (1/3)*4^2*x^2*4*9 = (4^2*4) ((1/3)*9) x^2 = 4^3*3*x^2=64*3x^2=64v}}}