Use ta=read.table(”TreeAgeDiamSugarMaple.txt”, header=T) to import the data set of diameter–age measurements for 27 sugar maple trees into the R data frame ta, and x=ta$Diamet; y=ta$Age to copy the...

Use ta=read.table(”TreeAgeDiamSugarMaple.txt”, header=T) to import the data set of diameter–age measurements for 27 sugar maple trees into the R data frame ta, and x=ta$Diamet; y=ta$Age to copy the diameter and age values into the R objects x and y, respectively.

(a) Would you expect the diameter and age to be positively or negatively correlated? Explain your answer, and confirm it by doing a scatterplot of the data (plot(x,y)).

(b) Compute the sample covariance and linear correlation of diameter and age using R commands. On the basis of the scatterplot are you satisfied that linear correlation correctly captures the strength of the diameter–age dependence?