The following were the recorded birth weights for babies born July 16, 2011: 8.1 lbs., 6.0 lbs., 4.7 lbs., 6.9 lbs., 5.6 lbs., 7.7 lbs., 6.3 lbs., 7.8 lbs., 6.1 lbs., and 9.2 lbs. What was the average birth weight on the day? Round to two decimal places.