The R data set wegs in the package "epitools contains the Western Collab- orative Group Study (WCGS) data to investigate the relationship between behavior pattern and the risk of coronary hearth disease (CHD). A number of other risk factors were also measured to provide the best possible assessment of the CHD risk associated with behavior type, such as the age, systolic blood pressure, cholesterol, and etc. Obtain the kernel density esti- mates for the distributions of cholesterol in the CHD and no-CHD groups separately. (b) (4 points) Use the Gaussian kernel and the unbiased cross validation to choose the smoothing parameter. Plot the density estimates for the CHD and no-CHD groups in one figure with a legend. What are the values you choose for the smoothing parameters for the CHD and no-CHD groups? (c) (4 points) Use the boxcar kernel (kernel = "rectangular") and the unbiased cross validation to choose the smoothing parameter. Plot the den- sity estimates for the CHD and no-CHD groups in one figure with a legend. What are the values you choose for the smoothing parameters for the CHD and no-CHD groups? (d) (2 points) Summarize in a paragraph the conclusions of the comparisons in part (b), and (c). The R data set wegs in the package "epitools contains the Western Collab- orative Group Study (WCGS) data to investigate the relationship between behavior pattern and the risk of coronary hearth disease (CHD). A number of other risk factors were also measured to provide the best possible assessment of the CHD risk associated with behavior type, such as the age, systolic blood pressure, cholesterol, and etc. Obtain the kernel density esti- mates for the distributions of cholesterol in the CHD and no-CHD groups separately. (b) (4 points) Use the Gaussian kernel and the unbiased cross validation to choose the smoothing parameter. Plot the density estimates for the CHD and no-CHD groups in one figure with a legend. What are the values you choose for the smoothing parameters for the CHD and no-CHD groups? (c) (4 points) Use the boxcar kernel (kernel = "rectangular") and the unbiased cross validation to choose the smoothing parameter. Plot the den- sity estimates for the CHD and no-CHD groups in one figure with a legend. What are the values you choose for the smoothing parameters for the CHD and no-CHD groups? (d) (2 points) Summarize in a paragraph the conclusions of the comparisons in part (b), and (c)