Exercise

Checking model fit

In the video you analyzed the example of an improvement in the model fit by adding additional variable on the wells data. Continuing with this data set you will see how further increase in model complexity effects deviance and model fit.

The dataset wells have been preloaded in the workspace.

Instructions

100 XP

Fit a logistic regression model with switch as the response and distance100 and arsenic as explanatory variables.
Compute the difference in deviance of the intercept only model and the model including all the variables.
Print the computed difference.