8. Yeast is often used in biological experiments. A research technician estimates that a sample of yeast suspension contains 2 million organisms per cubic centimeter. Two hours later, she estimates the population density to be 6 million organisms per cubic centimeter. Let t be the time elapsed since the first observation, measured in hours. Assume that the yeast growth follows the Law of Uninhibited Growth, that is the number of organisms N at time t is given by the formula N(t) = Noekt where N(0) = No is the initial number of organisms and k > 0 is a constant. (a) Find the growth constant k. Round your answer to four decimal places. (b) Find a function that gives the number of yeast (in millions) per cubic centimeter N(t) after t hours. (c) What is the doubling time for this strain of yeast?