Answer:
The question is incomplete, the complete question is "Changing Bases to Evaluate Logarithms in Exercise, use the change-of-base formula and a calculator to evaluate the logarithm. See Example 9.
.

Explanation:
From the general properties or laws of logarithm, we have the

where both log are now express in the natural logarithm base.
i.e

hence we can express our
.
the value of ln7 is 1.9459 and ln4 is 1.3863
Hence
.
