Answer
Sample answer:
$\ln M=\ln 10\cdot\log M$
$ ($if we know $\log M$, mulitply with $\ln 10$ to obtain $\ln M$)
Work Step by Step
Common logarithms: Instead of $\log_{10}x$, we write $\log x.$
natural logarithm: For base $ e\approx 2.7182818284$, we write $\ln x$ instead of $\log_{e}x.$
Using change-of-base, $\displaystyle \log_{b}M=\frac{\log_{a}M}{\log_{a}b}$, we change base 10 to $e$
$\displaystyle \log M=\frac{\ln M}{\ln 10}$
$\ln M=\ln 10\cdot\log M$
$ ($if we know $\log M$, mulitply with $\ln 10$ to obtain $\ln M$)
