Create a table with sales data with this video.
Insert the values in the table. Just set the name as 'sd' that means of sales data. Just imagine we have columns A to J. So start values with A2 and end with J9. In menu bar type as A2 to J9. It's just as to select as a table with those values. Now create another table and apply sd table values and statements insert like max, min, avg. In a row insert the formula for AVERAGE (sd) then apply you can get value sd's average. After that max row finding purpose insert MAX (sd) then you can get max value. After that min row finding purpose insert MIN (sd) then you can get min value.