Find a Mathematical Model Representing the Statement $( F = 24750 \text { when } r = 18 \text { and } s = 5 . )$

Multiple Choice

Find a mathematical model representing the statement.(Determine the constant of proportionality.)
F is jointly proportional to r and the third power of s. $( F = 24750 \text { when } r = 18 \text { and } s = 5 . )$

A) $F = \frac { 11 r } { s ^ { 3 } }$
B) $F = \frac { r s ^ { 3 } } { 11 }$
C) $F = 11 r s ^ { 3 }$
D) $F = \frac { 11 } { r s ^ { 3 } }$
E) $F = \frac { 11 s ^ { 3 } } { r }$