You deployed an AP and installed its antenna, and you now need to set the AP transmit power. Given a desired EIRP of 21 dBm, and an antenna

gain of 5.85 dBd connected through 25 feet of cable with a loss specification of 4 dB/100 feet.

Assuming that there is no significant loss from the connectors, what should be the transmit power level for this AP?