Column mean from certain rows - then populate mean in a new column
I'd like to calculate a column mean with the condition that it only includes the rows with a certain ID. In this case, I only want to average the data for the Blanks. I'd like the output to populate down a new column. The result will look like this: I know how to achieve this with the Table>Summary application, but I don't know how to do it in my data table + have it populate down. Thank you for t...