The constant of proportionality is the ratio between two directly proportional quantities. Two quantities are directly proportional when they increase and decrease at the same rate. The constant of proportionality k is given by k=y/x where y and x are two quantities that are directly proportional to each other.
If James has 12 pairs of basketball shoes, then the ratio would be 3:4 which would stop at 3:12. Then the individual ratios would be 3:4, 6:8, and 9:12
