Ratio of amplitudes of sound problem

[Amith2006]

Sir,
The intensity level due to 2 waves of same frequency in a given medium is 1 bel and 4 bel. What is the ratio of their amplitudes?
I solved it in the following way:
L1 = 10 decibels
L2 = 40 decibels
Loudness(L) = 10(log(I/Io))
Where I= Intensity of sound, Io = Intensity of weakest audible sound
Therefore,
10 = 10[log(I1/Io)]
Similarly,
40 = 10[log(I2/Io)]
Solving we get,
I1 = 10 Watt/m^2
I2 = 10000 watt/m^2
Intensity is proportional to (amplitude)^2
I1/I2 = a1^2/a2^2
a1/a2 = [I1/I2]^(1/2)
i.e. a1/a2 = [1/1000]^(1/2)
= 1/[10^(3/2)]
Is it right?

 

[Doc Al]

Sounds good to me.