I am creating a box and whisker graph using 4 data points: -53.8, -41.2, -27.0, and -26.5.  I would have expected the box would extend from the 2nd value to the 3rd value and the bottom whisker would extend to the minimum value and the upper whisker would extend to the maximum value.  Below is the graph I created in SAS where the box extends to the midpoint between the 1st and 2nd value (-47.5) to the midpoint between the 3rd and 4th value (-26.75), but the whiskers extend to the minimum and maximum.  Any ideas why SAS is computing 1st and 3rd quartiles in this manner?  With only 4 values, I would expect the median would divide the box evenly.           ... View more