I missed my last math class covering this topic and I am having
issues finding the right formula to use for the following
problems. Any help would be greatly appreciated.  In 2006, the
population of the United States reached 300,000,000 people. We
heard in the news that in 1967 the population had reached
200,000,000 people. We of course wonder when the population will
reach 350,000,000 or even 400,000,000. Find the function that
describes the current population of the United States and use
this function to determine in what year our population is
expected to reach 400,000,000. According to this model when was
our population 100,000,000?   On October 31, 2011 (Halloween),
the world population reached the 7 billion mark. In reporting
this news, we were told that the world population reached these
milestones: 1804 1 billion people 1927 2 billion people 1959 3
billion people 1974 4 billion people 1987 5 billion people 1999
6 billion people 2011 7 billion people  Let t be the number of
years after 1927. Find a fun