Audio Sampling Rate and Sampling size.

1. Sound moves through what medium?
   Sounds are pressure waves of air. If there wasn't any air, we wouldn't be able to hear sounds. There's no sound in space. 
2. What is used to measure sample size?
   Bits
3. What unit is used to measure sampling rate?
   Hz (hertz)
4. Compare the quality of AM, FM and Digital Radio.
   AM radio ranges from 535 to 1705kHz.
   FM radio band goes from 88 to 108 MHz.
   Digital radio has frequencies below 30MHz.