Your 1792 Erlangs appears to be the traffic for a whole month, right?
You must break it down to the Busy Hour, so…
Take 1702 divide by 22 business days in avg month (or actual, look at calander for month 1792 Erlangs generated for actual days), This provides average day Erlangs, then either take a percentage of the average day (an eight hour day provides 12% of anything for each hour, so if average busy hour is 20% higher, 12 * 1.2= 14.4 % or average day would give a good estimate of average busy hour. Use this number to input BHr Erlangs in the formula, and see the answer generated…should be aound 23 trunks for .01 PGOS.
Did I make my self clear? Hope so. Pax et bonum! (Peace and Goodness to you!)