Change of Base Formula

The change of base formula is very important because most calculators do not have a log to any base button.  This formula allows us to calculate any logarithm given only two bases on our calculator.

Apply the change of base formula as follows.

We could choose any base. However, it is wise to choose base e or 10 because there is a button for them on most calculators.

Evaluate using a calculator and round off to the nearest thousandth.

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