Y intercept (0 , 5)
The y intercept in context of the problem tells us that at 0 hour, there was already 5 wasps in the garden.
Rate of change: Using (0,5) and (1 , 9)
Rate of change = ( 9 - 5)/(1 - 0) = 4/1 = 4
Rate of change = 4 wasps per hour.
The rate of change in context of the problem tells us that there are 4 wasps in the garden per hour.