Problem 10-28 The following is a control chart for the average number of minor errors in 22 service reports.
a. Calculate the observed mean, expected mean, standard deviation and z value for the median and up/down test. (Negative amounts should be indicated by a minus sign. Round your answers to 2 decimal places.) Test Observed Expected Std. dev z Median Up/Down
I know some of these answers are incorrect. Please assist