I would suggest performing a leakdown test... that will tell you for sure.

Were you very careful to make sure you aligned and installed the timing belt correctly and tensioned the belt correctly as well? If you installed the belt off a couple teeth, or you didn't tension it properly it could have skipped teeth... which would cause piston to valve contact resulting in bent valves and low compression (although I think that your numbers would be more consistently low throughout all the cylinders if you bent valves, but its worth mentioning).

Also, make sure that you perform the compression test with both underhood ECU fuses removed and with the throttle FLOORED.