Use the logarithm change of base formula to convert each of the following logarithms to the specified base. Then use a calculator to approximate the logarithm. Round approximations to four decimal places. Convert log20 13 from base 20 to base 5. log20 13 which is approximately equal to Convert logg 10 from base 8 to base 10. logg 10- which is approximately equal to Convert log15 6 from base 15 to base e. log 15 6 which is approximately equal to