Igf13 The data set Igf13 contains the data from Igf for children under 13 years old. Most of the data was collected from physical examinations in schools.

1. Fit a linear regression to igƒ using age as the predictor variable. Comment on the appropriateness of the model.

2. Use the model from part a to predict igƒ for a 20-year-old person. Do you think this prediction is accurate? Support your answer briefly.

3. If your model does not satisfy the assumptions and conditions of regression, find a suitable transformation of igƒ and refit the model. Are the assumptions and conditions met for the new model?

4. Would you use the model in either part a or part c to predict igƒ for a 30-year-old person? Why or why not?

5. Predict igƒ for a 20-year-old person using the model in part c. Do you think this prediction is better than the one you found in part a? Do you think it is accurate? Support your answer briefly.