Exercise

# Cox Proportional Hazard Model

Now you are going to compute a Cox Proportional Hazard model on the online shop data. Your data stored in `dataNextOrder`

now contains four additional variables: the `shoppingCartValue`

of the first order in dollars, whether the customer used a `voucher`

, whether the order was `returned`

, and the `gender`

.

The `rms`

package is already loaded in the workspace.

Instructions

**100 XP**

- Compute the Cox PH model using
`cph()`

. Include the variables`shoppingCartValue`

,`voucher`

,`returned`

and`gender`

as predictors. Pay attention to specify the formula correctly. Store the result in an object called`fitCPH`

. And, of course, print the results. - Take the exponential of the
`coefficients`

to interpret them. With respect to interpretation, take into account that`shoppingCartValue`

is a continuous variable, whereas the remaining variables are categorical. - Plot the result summary.