Problem 6: following data shows the duration of pain relief after taking a particular medicine: Duration(hours) No. of patients 4 8 8 12 5 12 16 9 16 20 4 20 24 2 find 1. mean(average) duration of pain relief 2. variance and sd of duration of pain relief 3. what is conclusion about the variability(variation) of duration of pain relief 4. calculate coefficient of variation(C.V)