Energy of incident of light to amplitude of light?

chewchun

1. The problem statement, all variables and given/known data
A sheet of glass transmit 70% of the energy of the incident light
What is the value of the quantity: (Amplitude of transmitted light) / (Amplitude of incident light)
A:0.49
B:0.70
C:0.84
D:1.19


2. Relevant equations
Intensity is proportional to amplitude square.



3. The attempt at a solution
I tried relating to the above equation but i got 0.7^2/1^2=0.49 (A) but answer is not A...

Doc Al

Why did you square the ratio of intensities?