How do you use the Change of Base Formula and a calculator to evaluate the logarithm log_4 72?

Refer to explanation

Explanation:

Using the change of base of formula

log_(4)72=log72/log4=log(9*8)/log(2^2)=(2*log3+3*log2)/(2*log2)= 3/2+log3/log2

Now using a calculator we see that $\log 2 = 0.69$ and $\log 3 = 1.10$

so finally ${\log}_{4} 72 = 3.08$