with diabetes. They had their weights measured at baseline and again when they returned to camp 1 year later. Each time, a serum sample was obtained from which a determination of hemoglobin Alc (HgbAlc) was made. HgbAlc (also called glycosylated hemoglobin) is routinely used to monitor compliance with taking insulin injections. Usually, the poorer the compliance, the higher the HgbAlc level will be. The hypothesis is that a change in weight is associated with a change in the level of HgbAlc. The data in the table below were obtained. Assume that the distribution of weights and HgbAlc values are normally distributed. Use these data to answer the questions below the table. 1 st Visit 2nd Visit ID No. Weight (kg) HgbAlc (%) Weight (kg) HgbAlc (%) 40.5 9.9 45.5 8.4 2 43.2 11.3 47.0 9.2 3 36.3 10.4 42.0 9.6 4 30.8 7.4 35.3 8.1 5 29.9 9.8 33.2 7.9 6 39.7 8.5 46.1 7.7 7 36.9 7.3 37.8 7.7 8 36.4 7.8 37.0 8.4 9 34.5 7.8 34.3 9.6 10 35.2 5.7 38.4 6.5 11 43.0 7.4 48.6 7.4 12 38.4 6.5 42.7 7.0 13 42.0 7.1 48.0 7.4 14 34.1 8.9 41.3 8.1 15 43.5 9.3 51.4 7.4 a. Create an appropriate plot of the data to visually assess the linear relationship between the change in weight and change in level of HgbAlc. Comment on the nature and strength of the linear relationship between the two variables. b. Conduct a regression to test the hypothesis. Assume a=0.05. Is the hypothesis supported by the data? Explain. c. What is the percent variation in change in HbgAlc level explained by change in weight? d. What is the value of the slope in the regression equation you obtained in question a? What is the practical interpretation of the value of the slope