4.11 Case Study: Flood Watch: Quiz
Problem 4
Suppose that instead of the resulting blood donations given in the previous problem, there is no response to the advertising—that is, the donations stay at their base level. What is the new lag time? How can this be interpreted?
Answers, problem 4
The new lag time is −1.637. This at first seems to indicate that the centroid of the blood donations occurs before the centroid of the advertising. However, the x-coordinate of the centroid of the blood donations is 0, since there is no region above the base flow to calculate the centroid of. Therefore this should be interpreted to mean that the advertising has no effect on the rate of blood donations.