Question on Duncan calculation

On page 169 of Duncan, I have a question about Table 8.2. For program #2, when they calculate marginal net savings for the first 100 chronic members, they calculate it as (150,000- 50,000)/100. Where does the 150,000 come from?



I have a similar question for the next box down. The marginal net savings per chronic members for the next 400 members is (250,000 - 200,000)/400. Where does the 250,000 come from?



Thanks.

Question on Duncan calculation