In the Hypothetical Example That Follows, Patients Coming into a Clinic

In the hypothetical example that follows, patients coming into a clinic with disease symptoms are classified as having varying degrees of severity, from Stage 0 to Stage 4. Stage 4 represents the most severe symptoms; Stage 0 includes those with symptoms only but not the disease. The available treatment is expected to benefit those groups differently, and add extra years of life to each person as shown in the Gain (each person) row in the table. Please answer questions 5 through 7.
? $\begin{array}{|l|l|l|l|l|l|l|}\hline & \text {Stage 4 }& \text {Stage 3} & \text { Stage 2} & \text {Stage 1 }& \text {Stage 0 }& \quad\\\hline \text { Gain (each person) }& 45 & 30 & 4 & 1 & 0 & \\\hline \text {Number of persons coming to clinic }& 4 & 4 & 12 & 20 & 60 & \\\hline\end{array}$

-"Flat of the curve" medicine means that if patients with Stage 0 disease symptoms are treated, the marginal benefits of the treatment are less than the marginal cost of treating symptoms.