Refer to the data in Table 9.

(a) Using a graphing utility, build a logistic model from the data.

(b) Graph the logistic function found in part (b) on a scatter diagram of the data.

(c) What is the predicted carrying capacity of U.S. cell phone subscribers?

(d) Use the model found in part (b) to predict the number of U.S. cell phone subscribers at the end of 2009.

(e) Compare the answer to part (d) above with the answer to Example 1, part (e). How do you explain the different predictions?

Table 9

Year ………………………………… Subscribers (1,000)

1975 (t = 5) ……………………………………… 9,800

1980 (t = 10) …………………………………… 17,500

1985 (t = 15) …………………………………… 35,440

1990 (t = 20) …………………………………… 50,520

1992 (t = 22) …………………………………… 54,300

1994 (t = 24) …………………………………… 58,373

1996 (t = 26) …………………………………… 62,300

1998 (t = 28) …………………………………… 64,650

2000 (t = 30) …………………………………… 66,250

2002 (t = 32) …………………………………… 66,472

2004 (t = 34) …………………………………… 65,727

2006 (t = 36) …………………………………… 65,319