A rare plant that grows on the limestone cliffs of the Northern Swiss Jura mountains was studied in Alpine Botany (Nov. 2012). The researchers collected data from a sample of 12 limestone cliffs. Several of the variables measured for each cliff included the altitude above sea level (meters), plant population size (number of plants growing), and molecular variance (i.e., the variance in molecular weight of the plants). These data are provided in the accompanying table. The researchers are interested in whether either altitude or population size is related to molecular variance.

a. Use a scatter plot to investigate the relationship between molecular variance and altitude. Do you detect a trend?
b. Use a scatter plot to investigate the relationship between molecular variance and population size. Do you detect a trend?

Population Cliff Molecular Number Altitude Size Variance 468 147 59.8 209 589 24.4 3 700 28 42.2 4 664 177 59.5 876 248 65.8 17.7 909 53 1032 33 12.5 952 114 27.6 217 832 35.9 1099 13.3 10 10 11 982 3.6 12 1053 15 3.2