When the amplitude of a wave triples, the intensity changes by a factor of [blank] (1/3,1/9,3,9)
When the amplitude of a wave is cut in half, the intensity changes by a factor of [blank] (1/4,1/2,2,4)
When the distance between the source and your ear is ten times farther away, the intensity changes by a factor of {blank] (1/10,1/100,10,100)
When the distance between the source and your ear is reduced by 1/3, the intensity changes by a factor of [blank] (1/3,1/9,3,9)
