Question: Let f(t) be the number of US billionaires in the US in year t.
(a) Express the following statements in terms of f.
(i) In 1985 there were 13 US billionaires.
(ii) In 1990 there were 99 US billionaires.
(b) Find the average yearly increase in the number of US billionaires between 1985 and 1990. Express this using f.
(c) Assuming the yearly increase remains constant, find a formula predicting the number of US billionaires in year t.