In the article "Effects of Human Population, Area, and Time on Non-native Plant and Fish Diversity in the United States" (Biological Conservation, Vol. 100, No. 2, pp. 243-252), M. McKinney investigated the relationship of various factors on the number of exotic plants in each state. On the WeissStats site, you will find the data on population (in millions), area (in thousands of square miles), and number of exotic plants for each state. Use the technology of your choice to determine the linear correlation coefficient between each of the following:
a. Population and area
b. Population and number of exotic plants
c. Area and number of exotic plants
d. Interpret and explain the results you got in parts (a)-(c).