We’ve seen by using the PewHealth dataset that as one gets older, one’s score on the Cellphone Use Index goes down. But is this a linear or non-linear relationship? Run a set of nested models: the fi...

We’ve seen by using the PewHealth dataset that as one gets older, one’s score on the Cellphone Use Index goes down. But is this a linear or non-linear relationship? Run a set of nested models: the fi rst with the age variable alone, and the second with the squared age variable added. Create a table that includes both models; then create a graph and explain your results.