a. Steps to create a scatter plot to identify the best model by using a graphing utility.

1. Set corresponds to the year 1960

2. Set the window of the scatter plot as

3. Use table graph feature and enter the corresponding tabular values as

shown below:

0	180.671	35	263.044
5	194.303	38	270.561
10	205.052	40	281.422
15	215.973	43	294.043
20	227.726	65	358.030
25	238.466	90	408.695
30	249.948