Exercise

# Explore retention and churn

Now that you have calculated the monthly retention and churn metrics for monthly customer cohorts, you can calculate the overall mean retention and churn rates. You will use the `.mean()`

method twice in a row (this is called "chaining") to calculate the overall mean. You will have to exclude the first month values (first column) from this calculation as they are constant given this is the first month the customers have been active therefore their retention will be 100% and churn will be 0% for all cohorts.

The `pandas`

and `numpy`

libraries have been loaded as `pd`

as `np`

respectively. The `retention`

and `churn`

monthly datasets that you built in the previous exercises are also imported.

Instructions

**100 XP**

- Calculate the mean retention rate.
- Calculate the mean churn rate.
- Print rounded retention and churn rates.