The graph shows that from 2000 through 2006, Americans unplugged land lines and switched to cellphones.

a. Use the graphs to estimate the point of intersection. In what year was the number of cellphone and land-line customers the same? How many millions of customers were there for each?

b. The function 4.3x + y = 198 models the number of land-line customers, in millions, x years after 2000. The function y = 19.8x + 98 models the number of cellphone customers, in millions, x years after 2000. Use these models to determine the year, rounded to the nearest year, when the number of cellphone and land-line customers was the same. According to the models, how many millions of customers, rounded to the nearest ten million, were there for each?

c. How well do the models in part (b) describe the point of intersection of the graphs that you estimated in part (a)?

Transcribed Image Text:

Number of Customers (millions) 250 200 150 100 50 Number of Cellphone and Land-Line Customers in the United States Land-line Cellphone 2000 2001 2002 2003 2004 2005 2006 Year