Answer:
Four times.
Step-by-step explanation:
If wave y has twice the amplitude of wave x, then energy of wave y is four times because there is direct relationship between wave amplitude and wave energy. If amplitude of wave increases to double, the wave energy increases to four times. According to the formula, the energy transported by a wave is directly proportional to the square of the amplitude which means if one increase occur in the amplitude of the wave, double increase occur in the wave energy.