Question: In 2010, the world's population reached 6.91 billion and was increasing at a rate of 1.1% per year. Assume that this growth rate remains constant. (In fact, the growth rate has decreased since 1987.)
(a) Write a formula for the world population (in billions) as a function of the number of years since 2010.
(b) Estimate the population of the world in the year 2020.
(c) Sketch world population as a function of years since 2010. Use the graph to estimate the doubling time of the population of the world.