Use the graph representing bacteria decay to estimate the domain of the function and solve for the average rate of change across the domain.

an exponential function titled bacteria decay with x axis labeled time, in minutes, and y axis labeled amount of bacteria, in thousands, decreasing to the right with a y intercept of 0 comma 60 and an x intercept of 18 comma 0.

0 ≤ x ≤ 18, −3.33
0 ≤ x ≤ 18, −0.3
0 ≤ y ≤ 60, −3.33
0 ≤ y ≤ 60, −0.3