Suppose Charlene Brewster has timesâ (in seconds) of 8.5â, 8.5â, 8.3â, 8.6â, 8.7â, 8.4 and a performance rating of 85â%.
The normal time for this operationâ = _____ seconds â(round your response to two decimalâ places).
Based on the normal time and the observedâ times, Charlene's work performance should be rated as ______