The price of a first class postage stamp was raised from 37 cents to 39 cents on Jan. 8, 2006. The change followed the approval of a Postal Rate Commission recommendation to raise prices on all classes of mail approximately 5.4 percent.
The interquartile range (IQR) is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts.he interquartile range (IQR) is a measure of variability, based on dividing a data set into quartiles. Quartiles divide a rank-ordered data set into four equal parts.
The interquartile range, abbreviated IQR, is just the width of the box in the box-and-whisker plot. That is, IQR = Q3 â Q1. The IQR can be used as a measure of how spread-out the values are. Statistics assumes that your values are clustered around some central value. The IQR tells how spread out the middle values are; it can also be used to tell when some of the other values are too far from the central value.