#### Answer

2.0850

#### Work Step by Step

If $a\gt0$, $a\ne1$, $b\ne1$, and $x\gt0$, then we know that $log_{a}x=\frac{log_{b}x}{log_{b}a}$.
Therefore, $log_{4}18=\frac{log_{10}18}{log_{10}4}\approx\frac{1.2553}{0.6021}\approx2.0850$.
Recall that $b$ can be any positive number other than 1.