Chapter 17, Problem 27P

The concentration of E. coli bacteria in a swimming area is monitored after a storm:

Day	0	4	8	12	16	20
Amount $\times {10}^6$	67	84	98	125	149	185

The time is measured in hours following the end of the storm and the unit CFU is a “colony forming unit.” Use these data to estimate

(a) The concentration at the end of the storm $\left(t=0\right)$ and

(b) The time at which the concentration will reach 200 CFUy100 mL. Note that your choice of model should be consistent with the fact that negative concentrations are impossible and that the bacteria concentration always decreases with time.