All these questions refer to the dataUciOnlineRetail.xlsx dataset $($uploaded to Jupyter Hub$).$

Note: This file is large $($over $540K$ rows$/$observations and the reason why you might to filter it$)-$ it'll take up to a minute or so to read it in Jupyter Lab. While it is loading, you will see an asterisk next to the line of code. Only when that asterisk turns into a number does that indicate that the file is in your Jupyter Notebook environment and can be used.

Also, remember that you cannot preview an excel file from within Jupyter Hub by double$-$clicking the file. If you try to do this, you'll get an error.

All the hints below assume that you have loaded the data in a variable called $"$df$".$