Shower draining too slowly

I should have put in my original response that we had already tried pulling out the hair clog with a zipit but the clog was past its reach. On our particular drain, at about 3 feet from the drain there is a 90 degree turn where it meets up with the sink drain. We suspect that is where the clog was because the sink still drained fine. We also didn't just fire up the hose at full pressure. I turned on the sprayer a little at a time while Dave watched outside to see what was coming out the clear sewer connector. Dave saw two large clumps come out and then the drain ran freely.