Refer to the Alpine Botany (Nov. 2012) study of rare plants that grow on the limestone cliffs of the Northern Swiss Jura mountains, Exercise 2.165 (p. 97). Data on 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) for a sample of 12 limestone cliffs are reproduced in the table. Recall that the researchers are interested in whether either altitude or population size is related to molecular variance.

a. Use simple linear regression to investigate the relationship between molecular variance (y) and altitude (x). Find and interpret the value of r2.
b. Use simple linear regression to investigate the relationship between molecular variance (y) and population size (x). Find and interpret the value of r2.
c. What are your recommendations to the researchers?

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