Chapter 9, Problem 30E

To determine

To create a model that describe this trend and justify decisions you make how to best use these data.

Explanation of Solution

The national center of health statistics reported the data below, showing the percentage of all births that are to unmarried women for selected years between $1980\text{ and 1998}$ . Now, we have to create the model for these data. So, the data of percentage of unmarried women given in the question is as:

Year	1980	1985	1990	1991	1992	1993	1994	1995	1996	1997	1998
%	18.4	22	28	29.5	30.1	31	32.6	32.2	32.4	32.4	32.8

Thus, the model can be separated into two parts as we can see from the data that the slope of $1980-1994$ is much larger than the slope of the years between $1994-1998$ as they have straight form of points. The scatterplot of the two data sets form are as follows:

  

And the second scatterplot is as:

  

Thus for both the unmarried women percentages in on the vertical axis and the years is on the horizontal axis.