Please Read Question Below!

Question

Year	1990	1993	1996	1999	2002	2005
Number	5	16	44	86	141	206

The table shows the number of cellular phone subscribers (in millions) in the United States for selected years.

(a) Use the regression capabilities of a graphing utility to find a mathematical model of the form y = at² + bt + c for the data. In the model, y represents the number of subscribers and t represents the year, with t = 0 corresponding to 1990. (Round your coefficients to three decimal places.)

b) Use a graphing utility to plot the data and graph the model.

(c) Use the model to predict the number of cellular phone subscribers in the United States in the year 2025. (Round your answer to three decimal places.)

Answer 1

a) you'll need to graph this data on your calculator or other graphing utility.

generally, you do this by adding the data (x & y coordinates) to some kind of list.

then, you need to perform a regression analysis (which is essentially a fancy math way of saying creating a line of best fit) on your graphing utility. it's important in this step, that you are performing the regression to model your data to behave as a PARABOLIC function (that is, the standard quadratic formula y = ax^2 + bx + c).

in doing this previous step, your calculator will print out info on what a, b, and c are. a/b/c will be the constants/coefficients they want.

BE SURE throughout this process, to read the instructions from the problem AS you complete the steps. they have some requirements for you about decimal places/etc.

b) so where step a is asking you to find a FUNCTION/formula to describe the data, step b wants you to actually show the graph. do so, again, using your graphing calc/utility.

c) here you'll use your graph of the FUNCTION (do NOT use the data from the problem, use the actual parabola on your graph since it is your tool for estimation) to predict the number of cellular phone subscribers in the United States in the year 2025.