7. Create a scatterplot to investigate the association between the amount of fluoride in domestic water (ppm) and the number of dental caries in permanent teeth per 100 children for 21 cities. The data are below. a) Create the scatterplot b) Describe the association you see in your scatterplot. c) The value of r is -0.86, -0.36, 0.36, or 0.86? CityID FLUORIDE (ppm) CARIES 1 1.9 236 2 2.6 246 3 1.8 252 4 1.2 H 258 5 1.2 281 6 1.2 303 7 1.3 323 8 0.9 343 9 0.6 412 10 0.5 444 11 0.4 556 12 0.3 652 13 0.0 673 14 0.2 703 15 0.1 706 16 0.0 722 17 0.2 733 18 0.1 772 19 0.0 810 20 0.1 823 21 0.1 1037 Data from Dean, H.T., Arnold, F. A., Jr., & Elvove, E. (1942). Domestic water and dental caries. Public Health Reports, 57, 1155-1179