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

0 ≤ y ≤ 80, −0.6875
0 ≤ y ≤ 80, −1.45
0 ≤ x ≤ 55, −1.45
0 ≤ x ≤ 55, −0.6875