3. Below is a typical graph of the number / of bacteria grown in a batch culture as a function of time t. Describe what you think is happening during each of the four phases. N 4 4. A Boeing 747 crosses the Atlantic Ocean (3000 miles) with an airspeed of 500 miles per hour. The cost C (in dollars) per passenger is given by T 36, 000 C(x) = 100 + 10 +