Find the Constant of Proportionality for the Stated Conditions $E$ Varies Jointly With

Multiple Choice

Find the constant of proportionality for the stated conditions: $E$ varies jointly with $I$ and $R$ , and when $E$ $= 2,520 , R = 40$ and $\mathrm { I } = 7$ .

A) $\quad k = 7$
B) $k = 9$
C) $\quad k = - 9$
D) $\quad k = - 2,520$
E) $\quad k = 2,520$