The percentages of U.S. households with only a cell phone (no landline phone) are shown in Table 42 for various years.
Table 42
Percentages of U.S. Households with Only a Cell Phone
Year Percent
2003 …………………….. 2
2005 …………………….. 8
2007 ……………………..13
2009 ……………………..22
2011 ……………………..31
2013 ……………………..39
a. Construct a time-series plot.
b. Has the percentage of U.S. households with only a cell phone increased, decreased, stayed approximately constant, or none of these?
c. Find the greatest change for a 2-year period in the percent- age of U.S. households with only a cell phone.
d. Find the change in the cell phone–only percent from 2003 to 2013. If the cell phone–only percent changes by the same amount from 2013 to 2023, what will it be in 2023? Do you have much faith that this will turn out to be true? Explain.