Answer
$\log_e{M}= 2.2\text{ }$ OR $\text{ }\ln{M} = 2.2$
Work Step by Step
RECALL:
$a^x=y \longrightarrow \log_a{y}=x$
Thus, the logarithmic equivalent of the given equation is:
$\log_e{M}= 2.2$
This expression is equivalent to $\ln{M} = 2.2$