98% is the highest percentile you can get on the quant section.
The GMAT prep exams are the best indication for the real exam, but you will see variations among all exams. Your scores likely represent a fair range of what you can expect on the real thing.
If my response helps, please add throw me a kudos.
Jim Kernan is the Director of GMAT Operations at Stratus Prep and author of GMAT Materials for GMAT Prepster.