What is the relationship between propagation and density change?

Density affect propagation.

Density is mass per unit volume of a substance.

A substance that is more sense has more mass per unit volume, it will make sound to transmit at slower rate . Less dense substance will allow sound to transmit at higher rates. Density affect the speed a wave will be transmitted through it. The denser the material, the slower wave will be transmitted.

Explanation:

Density is Mass per unit volume. Density affect the propagation of wave. The denser the substance, the slower wave will be transmitted through it. The less dense the material, the higher wave will be transmitted through it. Density affect the speed of wave.