In reply to Rick Wicklin.

Hi Rick, thank you for the quick reply. However, I'm still feeling a little confused.
For instance, in the resulting plot, at the first time point, weight group 1 has a score around 2.5, while weight group 2 has a score around 3.5.
I got the predicted values from the "OUTpredm=" dataset.
How are the values of 2.5 or 3.5 calculated from the predicted values? (I attempted to calculate the predicted mean, but the results were not around 2.5 or 3.5)