Answer:
[tex]{ \tt{4 log_{4}(3100) }} \\ = { \tt{4 log_{4}(775 \times 4) }} \\ = { \tt{4 log_{4}(775) + 4 log_{4}(4) }} \\ = { \tt{4( (\frac{ log_{10}775 }{ log_{10}4 } ) +1)}} \\ = { \tt{4(4.8 + 1)}} \\ = { \tt{23.2}}[/tex]