You have the following expression:
[tex]\text{log}_419[/tex]
In order to calculate the previous expression, use the following property:
[tex]\log _ab=\frac{\log b}{\log a}[/tex]
Then, for the given expression, you have:
[tex]\log _419=\frac{\log 19}{\log 4}\approx2.12[/tex]
Hence, the result is approximately 2.12
