InterQuartile Range (IQR) calculator Formula:
    The rank-ordered data is first divided into four equal parts. The denote number of these parts are Q1, Q2, Q3 repectively. Q2 is the median of the data set, Q1 is the median of the first half data set, and Q2 is the median of the second half of the data set. The Interquartile Range (IQR) value equals Q3 - Q1.