Dissecting the best flight duration model

You just set up a CrossValidator to find good parameters for the linear regression model predicting flight duration.

Now you're going to take a closer look at the resulting model, split out the stages and use it to make predictions on the testing data.

The following have already been created:

The flights data have been randomly split into flights_train and flights_test.

100 XP

Retrieve the best model.
Look at the stages in the best model.
Isolate the linear regression stage and extract its parameters.
Use the best model to generate predictions on the testing data and calculate the RMSE.