The scatter plot shows the estimated population of bacteria in a petri dish at various times, in hours, after an experiment began. What was the average rate of increase in the bacteria population per hour between 2 hours and 4 hours?

Data Points for Scatter Plot:
(0, 100)
(1, 150)
(2, 225)
(3, 338)
(4, 507)
(5, 760)