i want to output my average with a comma and decimal values like x,xxx.xx in sql

Question

I want to output my average value with a comma, like:

x,xxx.xx

Currently, I am getting my output as 1,295 but I need to include decimal places like 1,295.17. What's going wrong?

SELECT 
  Format(
    Avg(
      Abs(
        a - (
          SELECT 
            a 
          FROM 
            my_table 
          WHERE 
            num = '987535'
        )
      )
    ), 
    '#'
  ) 
FROM 
  my_table 
WHERE 
  num != '987535';

Expected result:

1,295.17

Actual result:

1,295