30. A water company employee measured the water level (in centimeters) in a reservoir during March and computed the average rates of change in Table 1.14. (a) What are the units of the average rates of change in Table 1.14? (b) Interpret the average rates of change in context. (c) For each time interval, what was the total change in water level? (d) Draw a possible graph of the water level as a function of time. Table 1.14 Interval (days) 1