1. Use the data set you used in HW 3 and answer the following questions.
a. Do a LOESS fit for Calories using the variables: weight, height, protein, carbohydrates, calcium and gender and look at the relationship that LOWESS provides and comment.
b. Take the residuals versus predicted plot that you ran for HW3 diagnostics and LOWESS it. Do you see any patterns? Should you?
2. You are given the data on time of exposure(x) and photolytic damage (y) for an exposed surface on the web as DATA for HW5_nlindata.
The scientists believe that the model relating damage and time is given by:
damage = Theta1 - Theta2 * exp(-Theta3 * time)
a. Estimate the parameters theta1, theta2 and theta3 and test for the significances of the parameters. Use your estimates to predict y given x. What can you say about the model?
b. Use bootstrapping to verify your results.
c. Do a LOWESS plot to compare your linear and non-linear fit.
