There are situations in which you want to display advanced statistics in your Chartmat Block. However, note that Chartmat does not replace your Spreadsheet and the functionalities of Google Sheets. Instead it gives you an easy to use interface to build apps and data visualizations on top of it. 

Therefore if you want to include statistics or derived values in your Chartmat Block it is best to prepare these in your Google Spreadsheet. In the video below I walk you through how to handle this.