The noise levels at 30 locations near an outdoor concert venue were measured to the nearest decibel. The data collected is shown in the grouped frequency table. Noise (decibels) 65-69 70-74 75-79 80-84 85-89 90-94 95-99 Frequency

(f) 1 4 6 6 8 4 1 a Calculate an estimate of the mean noise level. b A noise level above 82 decibels was considered unacceptable. Estimate the number of locations that had unacceptable noise levels.

AppendixLO1