Question 22 10 Points The following refer to the output shown on four variables, each of twenty cases. The variables are free fatty acid level (ffa), age (age), weight (weight) and skin fold thickness (skinfold). Call: Im(formula = ffa - age + weight + skinfold) Residuals: Min 10 Median 30 Max -0.23163 -0.16706 -0.03901 0.11602 0.49567 Coefficients: Estimate Std. Error t value Pr( > It| ] [Intercept) 3.95777 1.40138 2.824 0.01222 * age -0.01912 0.01275 -1.499 0.15323 weight -0.02007 0.00613 -3.274 0.00478 * * skinfold 0.07788 0.31377 -0.248 0.80714 Signif. codes: 0 0.001 '* * 0.01 't' 0.05 7 0.1 1 Residual standard error: 0.2224 on 16 degrees of freedom Multiple R-Squared: 0.4893, Adjusted R-squared: 0.3936 F-statistic: 5.11 on 3 and 16 degrees of freedom, p-value: 0.0114 a. Which variable seems to be an important predictor, and how does the R output confirm this? b. What does the R2 of 0.4893 say about the data? c. State the linear regression model as per the output. d. What does the residual shown in the output actually mean? Use the editor to format your