Swimming Pool Levels The graph of y = ƒ(x) represents the amount of water...

Swimming Pool Levels The graph of y = ƒ(x) represents the amount of water in thousands of gallons remaining in a swimming pool after x days.

(a) Estimate the initial and final amounts of water contained in the pool.

(b) When did the amount of water in the pool remain constant?

(c) Approximate ƒ(2) and ƒ(4).

(d) At what rate was water being drained from the pool when