A team of environmental epidemiologists used data from 23 counties to investigate the relationship between respiratory cancer mortality rates (Y) for a given year and the following three independent variables: X1 = air pollution index for the county; X2 = mean age (over 21) for the county; and X3 = percentage of workforce in the county employed in a certain industry. The sums of squares shown next can be used to summarize the key results from the regression of Y on X1, X2, and X3:
SSY = 2,387.653 SSE = 551.723
a. Determine the ANOVA table for the regression of Y on X1, X2, and X3.
b. Determine the R2-value for the model in part (a). Based on this value, comment on whether the pollution level, mean age, and percentage of people working in the particular industry appear to be related (as a group) to respiratory cancer mortality rates.