Answer:
3.4 volts
Step-by-step explanation:
For voltage gain, the number of decibels is 20 times the base-10 logarithm of the actual gain. Then the ratio of output to input is ...
20·log(Vout/Vin) = 18.6
Vout/Vin = 10^(18.6/20) ≈ 8.5114
So, the output voltage is ...
Vout = 8.5114·Vin = 8.5114·0.4 volts ≈ 3.4046 volts
The output voltage is about 3.4 volts.
