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 (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 values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively.1  Q1 is the middle value in the first half of the rank-ordered data set. 2  Q2 is the median value in the set.uartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively. 1  Q1 is the middle value in the first half of the rank-ordered data set. 2  Q2 is the median value in the set.