The average weight, $W,$ in pounds, of an adult is a function, $W=f(c),$ of the average number of Calories per day, $c,$ consumed.
(a) Interpret the statements $f(1800)=155$ and $f^{\prime}(2000)=0$ in terms of diet and weight.
(b) What are the units of $f^{\prime}(c)=d W / d c ?$