What is the name of your pattern and designer?
The increase is 2sts each for the front and back. It’s 2sts each for the sleeves. So there’s a total of 8sts at the raglans but this part of the pattern splits the increases between front and back, and sleeves. There will be more increases and more frequently at the front and back than at the sleeves.
For the 3rd size, front and back increases at the raglan seams inc on rows 1,3,5,7,9,11,13,15,17,19,21 and 23. That’s 48 sts increased.
For the sleeves, inc on rows 1,5,9,13,17 and 21. That’s 24sts increased.
The increases total 72sts taking you from 328 to 400sts.