Find the standard deviation of the following values: 2.58x10-5, 2.33x10-5, 3.28x10-5, 3.57x10-5

Find the range, sample standard deviation and inter-quartile range (IQR) of the following data set. 23 range = standard deviation (8) = IQR = 26 range = 45 51 IQR = (Please enter an exact answer.) A new number, 223, is added to the data set above. Find the range, sample standard deviation and IQR of the new data set. standard deviation = 54 54 60 65 83 97 (Please enter an exact answer.) (Round to one decimal place.) (Please enter an exact answer.) (Round to one decimal place.) (Please enter an exact answer.)

At a hair salon, customers arrive at the rate of 3 customers per hour. The standard deviation of the time between two consecutive arrivals is estimated as 9 minutes. On average, it takes a customer 25 minutes to complete the service (regardless of which hairdresser provides the service). The coefficient of variation of the service time is estimated as 0.8. What is the standard deviation of the service time in minutes?

The mean test score for a history test is 63 with a standard deviation of 9. The mean test score for a chemistry test is 23 with a standard deviation of 4. A student got a 66 on the history test and a 26 on the chemistry test, use Z-scores to determine the relative performance on each test. On which test did the student perform better, and why?