Question

# Table shows the number of cellular phone subscribers in the United States and their average monthly bill in the years from 2000 to 2010.

Equation, expression, and inequalitie

Table shows the number of cellular phone subscribers in the United States and their average monthly bill in the years from 2000 to 2010.
$$\begin{matrix}\text{Year}&\text{Subscribers}&\text{Average Local}\\ \ \text{ }\ &\text{(millions)}&\text{Monthly Bill (\)}\\ \text{2000}&\text{109.5}&\text{45.27}\\ \text{2001}&\text{128.4}&\text{47.37}\\ \text{2002}&\text{140.8}&\text{48.40}\\ \text{2003}&\text{158.7}&\text{49.91}\\ \text{2004}&\text{182.1}&\text{50.64}\\ \text{2005}&\text{207.9}&\text{49.98}\\ \text{2006}&\text{233.0}&\text{50.56}\\ \text{2007}&\text{255.4}&\text{49.79}\\ \text{2008}&\text{262.7}&\text{50.07}\\ \text{2009}&\text{276.6}&\text{48.16}\\ \text{2010}&\text{300.5}&\text{47.21}\\ \end{matrix}$$
One of the scatter plots clearly suggests a linear model. Use the points at t = 10 and t = 20 to find a model in the form y=mx+b.