A gemologist is interested in determining the relation that exists between the size of adiamond (carats) and the price. The following data represents the weight and 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 use the number of carats to predict price. Determine which variable is the predictor variable and which is the response variable.
b. Draw a scatter diagram of the data.
c. Compute the linear correlation (Pearson) coefficient between the number of carats and the price of a diamond.
d. Comment on the type of relation that appears to exist between the number of carats and the price, based upon the scatter diagram and linear correlation coefficient.