Question: In 2007 it was estimated that about 1.7 billion text messages were sent each day in the United States, and in 2009 it was estimated that this number was 4.1 billion. Assuming the growth in texting is linear, set up a function for the number N of daily text messages and the time t in years, with t = 0 being 2007.
Sketch the graph for t = 0 to t = 8.