The graph shows the proportional relationship between the number of gems collected and the number of levels that have been completed in a video game.

Graph with x axis labeled game levels and y axis labeled gems collected. A line begins at 0 comma 0 and goes through points 6 comma 450 and 8 comma 600.

Determine the constant of proportionality for the relationship.

p equals 2 over 150
p = 0.0133
p = 75
p = 150