1. Fit the following models, and for each interpret the slope and the intercept.

Note: Model 4 requires the use of multiple regression. Suppose your data frame is called df, your response variable is y, and your explanatory variables are x1 and x2. You can fit this model with

lm(y ~ x1+ x2, data = df)

and use functions like tidy(), glance(), augment() on the model object. For interpretations of coefficients, refer to your reading from Chapter 8 of OpenIntro Statistics.

  1. Report and interpret the \(R^2\) values of the models you built above.

  2. Using Model 4, calculate the price of a new painting. You’ll need to come up with new hypothetical values for the attributes of this new painting for the explanatory variables you used in your model. Make sure you’re not extrapolating, and show how you checked this in your answer.

  3. Describe why transformations of variables might complicate model interpretations more so than predictions made on a model.