The formula for the volume of a square based pyramid is:
[tex]V={ a }^{ 2 }\cdot \frac { h }{ 3 } [/tex]
{Source: Google}
You've stated that:
[tex]a=7\\ \\ h=19[/tex]
Therefore:
[tex]V={ 7 }^{ 2 }\times \frac { 19 }{ 3 } =\frac { 931 }{ 3 } [/tex]
So the approximate volume of the square based pyramid is:
310 inches³ {Answer: C}
