3.7 Exercises Problem 10

10. This question should be answered using the Carseats data set.

(a) Fit a multiple regression model to predict Sales using Price, Urban, and US.

(b) Provide an interpretation of each coefficient in the model. Be careful-some of the variables in the

model are qualitative!

(c) Write out the model in equation form, being careful to handle the qualitative variables properly.

(d) For which of the predictors can you reject the null hypothesis HO: Bj=0?

(e) On the basis of your response to the previous question, fit a smaller model that only uses the

predictors for which there is evidence of association with the outcome.

(f) How well do the models in (a) and (e) fit the data?

https://wustl.instructure.com/courses/111056/assignments/559857

2023/10/18 17:46

Individual Assignment 1

(g) Using the model from (e), obtain 95% confidence intervals for the coefficient(s).

(h) Is there evidence of outliers or high leverage observations in the model from (e)?

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