ABSTRACT
Frequency distributions are visual displays that organize and present frequency counts so that the information can be interpreted more easily. Frequency distributions show the number of times a given quantity occurs in a set of data. The primary purpose of frequency distributions is to assist the researcher to make sense of the data collected. A more efficient way to present the data set and one which conveys more meaning is to list the 100 IQ scores in terms of their frequency of occurrence, that is, the scores frequency distribution. Grouping scores into class intervals are akin to collapsing the entire distribution of individual scores into classes in which the interval width of the classes is defined. A percentile rank (PR) is simply the reverse of calculating a percentile. Whereas a percentile is concerned with calculation of score below which specified percentage of scores fall, percentile rank is concerned with calculation of percentage of scores that fall below a given score.
