A. Quartiles divide an ordered set of data into four equal parts. There are 3 quartiles: Q1 (one-quarter of the data fall on or below the first quartile, Q2 (median), Q3 (three-quarters of data will fall on or below the third quartile Each of these portions contains 25% of the observations of a data set arranged in increasing order 25% 25% 25% 25% Q1 22 Q3 IQR = Interquartile range = Q3 - Q1 Ex. 1 The following are the ages (in years) of nine employees of an insurance company: 47 28 39 51 33 37 59 24 (a) Find the values of the three quartiles. Where does the age of 28 years fall in relation to the ages of the employees? (b) Find the interquartile range.