In the article “Iron overload indices rise linearly with transfusion rate in patients with sickle cell disease” published in Blood, the authors reported a simple linear regression model for relating serum ferritin (SF) to total lifetime transfusions (TLT).

The resulting fitted model, based on the records of ???? = 52 patients, is

ˆSF = 17.11 + 66.84 × TLT with a sample correlation of ???? = 0.835. Determine

(a) the strength of the linear relationship between SF and TLT according to Table 8.1, assuming the data cloud in the scatterplot of SF versus TLT is linear.

(b) the least squares estimate of the ????-intercept?

(c) the least squares estimate of the slope?

(d) the predicted value of SF for TLT= 100.

(e) the estimated expected change in SF for a one unit increase in TLT.