Chapter P, Problem 19PS

If the population of the world on October 12,2002, was 6.248 billion, when do you think the world population should have reached 7 billion? Calculate the date (to the nearest month) using the information that the world population reached 6 billion on October 12,1999. The world population actually reached 7 billion on October 31,2011. What does this say about your prediction?