Patrick has a total of 600 meters skein of yarn.
He used 248.9 meters of yarn to make a hat.
Now, If he has used 248.9 meters of yarn, we need to find how much yarn has he left.
We need to subtract the amount of yarn used from the total length. That is, 248.9 from 600.
So, now Patrick has left 351.1 meters of yarn.
Patrick needs to make a scarf that needs 354.03 meters of yarn but after making a hat he has left with only 351.1 meters of yarn. Therefore, Patrick does not have enough yarn to make a scarf.