You're attending a concert and you're curious about the power of the loudspeakers being used. The main loudspeaker, installed on a tower on the stage, is designed to project 82% of its acoustic energy toward the audience, and 18% toward the backstage area. While standing 2.3 meters in front of and 1.2 meters below the loudspeaker, you measure a sound intensity level of 92 dB. Calculate the power output of the loudspeaker.

• A. 8.5 × 10 ^-4 W
• B. 7.8 ×10 ^-4 W
• C. 8.2 × 10 ^-2 W
• D. 7.7 × 10 ^-2 W

Answer: (C)