Answer
True.
Work Step by Step
Apply the change of base property:
$\displaystyle \quad \log_{b}M=\frac{\log_{a}M}{\log_{a}b}$
(on the LHS, change base from 3 to 7)
$\displaystyle \log_{3}7=\frac{\log 7}{\log 3}$
Apply the basic property $\log_{b}b=1$
$=\displaystyle \frac{1}{\log_{7}3}$=RHS
Thus, the statement is true.
