A gemologist is interested in estimating the relation which exists between the size of a diamond (carats) and the price. The following data represents the weight as well as price of diamonds.
Carats Price (thousand dollars)
0.66 $3.3
0.75 $3.9
0.70 $3.5
0.71 $3.8
0.77 $4.1
0.80 $4.4
0.90 $5.7
0.91 $6.4
1.18 $9.4
a. The researcher wants to employ the number of carats to predict price. Find out which variable is the predictor variable and which is the response variable.
b. Draw a scatter diagram of data.
c. Calculate the linear correlation (Pearson) coefficient between the number of carats and the price of a diamond.
d. Comment on the kind of relation which appears to exist between number of carats and the price, based upon the scatter diagram and linear correlation coefficient.