1. One-way ANOVA using a categorized continuous predictor.

Use the individualized Louisiana cholesterol data set (chol_XXX.sas7bdat, where XXX is your Individual Data Set Number from Blackboard) to investigate the association between triglycerides and BMI. We will use log(Tg) rather than Tg as we have found it better satisfies the LINE assumptions.

1. (P, O)Create a new variable (bmicat) that has four equal-sized categories based on quartiles of the BMI distribution with values 1,2,3,4 for each quartile that are appropriately labeled using a format. Verify that you have 48 subjects in each bmicat group by using PROC FREQ.

1. (W, P, O)Create a scatterplot of log(Tg) vs. BMI (include a simple linear regression line), and then a boxplot displaying the mean of log(Tg) for each bmicat category. What do you conclude from these plots?

1. (W, P, O)Perform a one-way ANOVA to determine whether log(Tg) is associated with bmicat. Use an appropriate multiple comparisons procedure if your overall F-test is significant. Summarize your conclusions.