Answer:
Wave W is a sound wave, Waves X and Y are light waves, and it is impossible to tell what kind of wave Wave Z is.
Step-by-step explanation:
W travels fastest through metal
X travels fastest through air,
Y travels more slowly through water than air
Z travels more slowly at cool temperatures
W appears to be sound wave as sound travels fastest through metal .
X appears to be light wave as light travels fastest in air .
Y also appears to be light wave as speed of light is reduced when it passes from air to water .
Z It is impossible to tell anything about the nature of Z wave .