Remember that the whiskers on a boxplot can extend 1.5 interquartile ranges (IQRs) from either end of the box, and values beyond that range are considered to be outliers. For normally distributed data, the mean and median are equal and are both centered in the middle of the box in a boxplot.
a. Draw the “box” part of a boxplot for normally distributed data. What fraction of an IQR is the distance between the mean/ median and the ends of the box?
b. For normally distributed data, how many IQRs above or below the mean/ median would a data value have to be in order to be considered an outlier?