It depends on how many tests you have had.  The fewer tests you've
already had in getting that 92 average, the more the 33 will hurt 
your grade.

The more tests you have had in gatting that 92 average, the less the
33 will hurt your grade.

I'll assume each test counts the same.  If so then:

If you've had N tests, your average is now ,
so that 33 has dropped your grade by  points.

If you've had 2 tests, your average is now 62.5,
so that 33 has dropped your grade by 29.5 points.

If you've had 3 tests, your average is now 72.3333333,
so that 33 has dropped your grade by 19.6666667 points.

If you've had 4 tests, your average is now 77.25,
so that 33 has dropped your grade by 14.75 points.

If you've had 5 tests, your average is now 80.2,
so that 33 has dropped your grade by 11.8 points.

If you've had 6 tests, your average is now 82.1666667,
so that 33 has dropped your grade by 9.83333333 points.

If you've had 7 tests, your average is now 83.5714286,
so that 33 has dropped your grade by 8.42857143 points.

If you've had 8 tests, your average is now 84.625,
so that 33 has dropped your grade by 7.375 points.

If you've had 9 tests, your average is now 85.4444444,
so that 33 has dropped your grade by 6.55555556 points.

If you've had 10 tests, your average is now 86.1,
so that 33 has dropped your grade by 5.9 points.

If you've had 11 tests, your average is now 86.6363636,
so that 33 has dropped your grade by 5.36363636 points.

If you've had 12 tests, your average is now 87.0833333,
so that 33 has dropped your grade by 4.91666667 points.

If you've had 13 tests, your average is now 87.4615385,
so that 33 has dropped your grade by 4.53846154 points.

If you've had 14 tests, your average is now 87.7857143,
so that 33 has dropped your grade by 4.21428571 points.

If you've had 15 tests, your average is now 88.0666667,
so that 33 has dropped your grade by 3.93333333 points.

If you've had 16 tests, your average is now 88.3125,
so that 33 has dropped your grade by 3.6875 points.

If you've had 17 tests, your average is now 88.5294118,
so that 33 has dropped your grade by 3.47058824 points.

If you've had 18 tests, your average is now 88.7222222,
so that 33 has dropped your grade by 3.27777778 points.

If you've had 19 tests, your average is now 88.8947368,
so that 33 has dropped your grade by 3.10526316 points.

If you've had 20 tests, your average is now 89.05,
so that 33 has dropped your grade by 2.95 points.

Edwin