Refer to the data for 1200 patients with rheumatoid arthritis (CALCIUM). One hundred patients received the medicine at each dose level. Suppose you are a medical researchers wishing to gain insight into the nature of the relationship between dose level of prednisolone and total body calcium.

Select a simple random sample of three patients from each dose level group and do the following.

(a) Use the total number of pairs of observations to obtain the least-squares equation describing the relationship between dose level (the independent variable) and total body calcium.

(b) Draw a scatter diagram of the data and plot the equation.

(c) Compute r and test for significance at the .05 level. Find the p value.

(d) Compare your results with those of your classmates.