Exercise

Compare two models

From previous exercise you have fitted a model with distance100 and arsenic as explanatory variables. In this exercise you will analyze the impact on the model fit for each of the added variables.

Recall that the models you fitted are as follows and have been preloaded in the workspace:

model_dist = 'switch ~ distance100'
model_dist_ars = 'switch ~ distance100 + arsenic

The dataset wells has also been preloaded in the workspace.

Instructions

100 XP

Compute the difference in deviance when distance100 is added to the null model.
Compute the difference in deviance when arsenic is added to the model with distance100 variable.

Take Hint (-30 XP)