The accompanying scatterplot shows observations on hemoglobin level, determined both by the standard spectrophotometric method (y) and by a new, simpler method based on a color scale (x) (€œA Simple and Reliable Method for Estimating Hemoglobin,€ Bulletin of the World Health Organization [1995]: 369€“373):

a. Does it appear that x and y are highly correlated?
b. The paper reported that r = .9366. How would you describe the relationship between the two variables?
c. The line pictured in the scatterplot has a slope of 1 and passes through (0, 0). If x and y were always identical, all points would lie exactly on this line. The authors of the paper claimed that perfect correlation (r = 1) would result in this line. Do you agree? Explain your reasoning.

Reference method (g/di) 16 14 12 10 2 4 6 8 10 12 14 New method (g/dl)