Your initial answer of 7.23 is correct, however 7.23 x 10^3 is equal to 7230 and not 7.23 so therefore this is not right. Also, when in doubt in future problems always round to 3 significant figures unless otherwise specified.
I've heard that medstart is an ok resource for umat practise. Don't exactly know whether any of these are worth it or not but I'm going to give Medentry a crack anyway lol
Seriously what is wrong with you. Who gives a shit whether they're doing advanced or standard that's not even the point of this thread!
Anyway, OP I suggest reflecting on what worked well for you throughout the year and what didn't work so well. Ask questions as to where you went wrong. Was it...