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 = Q 3 â Q 1. 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.he  interquartile range, abbreviated  IQR , is just the width of the box in the box-and-whisker plot. That is, IQR = Q 3 â Q 1. 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.