In the case of known m and s, what control limits

Statistics 201 9/06/16  Dispersion­ spread ­Info about location (avg or median)  Range­ difference between max and min ­Range=max­min  Positive/right skew ­ mean is pulled to the right, and is larger than the median  Negative/left skew ­mean is pulled to the left, and is smaller than the median  Symmetric/bell shaped ­ mean is approximately the same as median  IQR= Q ­Q3 1 ­ is not effected by extreme values b/c os ca;culated using values that lie close to the center of the data set. IQR is not used in inferential statistics but are useful as descriptive statist