Final answer:
The approximation of log9 1,620 to six decimal places is 2.082074 (option A).
Step-by-step explanation:
The approximation, to six decimal places, of log9 1,620 is 2.082074 (option A).
To find this approximation, you can use a calculator. The calculator will give you the answer as 2,085.5688, but we need to round it to six decimal places. Since the seventh decimal place (in the ten-thousandths place) is greater than 5, we round up the sixth decimal place to 2.082074.