Answer:
69.54
Step-by-step explanation:
A power ratio of 9000000:1 corresponds to 69.54 dB.
The calculation is presented below:
Formula for calculating Power ratio (db) = 10 * log [P(out)/P(in)]
Since the given ratio is 9000000:1, substituting in the formula gives us 10 * log (9000000/1)
Note that log 9000000 = 6.954
Therefore, 10 * log (9000000/1) = 69.54
Hence the required power ratio in db is 69.54 db.