In 2008, about 66 million U.S. households had both landline phones and cell phones. This number decreased by an average of 5 million households per year. Use the table below to calculate the rate of change for the interval [2008, 2011].

[list=1][br][*]Determine the interval to be observed.[br][*]Determine [math](x_1, y_1)[/math].[br][*]Determine [math](x_2, y_2)[/math].[br][*]Substitute [math](x_1, y_1[/math]) and [math](x_2, y_2)[/math] into the slope formula to calculate the rate of change.[br][/list]