This problem uses the data from Problem 13 in Chapter 5. Use = .10. a. Use

Question:

This problem uses the data from Problem 13 in Chapter 5. Use α = .10.
a. Use a computer program to fit a quadratic natural polynomial model for predicting latency as a function of weight minus average weight.
b.-e. Repeat parts (b) through (e) from Problem 8 for this analysis.
f. Compare the results obtained here to those obtained in Chapter 5.
In Problem 8
a. Use a computer program to fit a natural polynomial cubic model for predicting vocabulary size as a function of age in years. Provide estimated regression coefficients.
b. Using variables-added-in-order tests, determine the best model.
c. Report variables-added-last tests. Explain any differences between your results here and those you obtained in part (b).
d. Report appropriate collinearity diagnostics for the model, and evaluate them. Include predictor correlations.
e. Plot jackknife (or studentized) residuals against predicted values for the best model based on your results in part (b). Provide a frequency histogram or schematic plot of the residuals, and comment on it.