Find the Average Value of the Function Over the Region $\mathrm { f } ( \mathrm { Q } , \varphi , \theta ) = \varrho$

Multiple Choice

Find the average value of the function over the region.
- $\mathrm { f } ( \mathrm { Q } , \varphi , \theta ) = \varrho$ over the solid ball $\varrho \leq 18$

A) $\frac { 27 } { 2 }$
B) $\frac { 2 } { 27 }$
C) $18 \pi$
D) 18