Chapter 2.3, Problem 44E

U. S. Population The population (in millions) of the United States (excluding Alaska and Hawaii) $t$ years after $1800$ is given by the function $f(t)$ in Fig. 18 (a). The graphs of $f\text{'}(t)$ and $f"(t)$

are shown in Figs.18(b) and 18(c).

Figure 18 (a) Population (in millions) of the United States from $1800$ to $1998$.

What was the population in $1925$?

Approximately when was the population $25$ million?

How fast was the population growing in $1950$?

When during the last $50$ years was the population growing at the rate of $1.8$

million people per year?

In what year was the population growing at the greatest rate?