y=kx - is a proportional relationships,
where is k is a constant.
k=y/x
x 32 56 72
y 12 21 27
k 12/32=3/8 21/56=3/8 27/72=3/8
k=3/8, 3/8 =y/x, y= (3/8)x
First table: proportional, y= (3/8)x
-------------------------
x 30 36 42
y 36 42 48
k 36/30=6/5 42/36=7/6 48/42=8/7
Second table: not proportional.
