In this section, we discuss box-and-whisker plots and the five key values ... The key values are called a five-number summary, which consists of the minimum, first quartile, ... the set is put into increasing order, divides the data into two equal parts. ... First, we put the values in the data set into increasing order: 3, 5, 7, 8, 12, 13, ... The middle score for a set of data that has been arranged in order from least to ... A box-and-whisker plot shows the distribution of a set of data along a ... Quartiles are values that divide a set of data into four equal parts. ... Second Quartile ( designated Q2) also called the median or the 50th percentile (cuts data set in half ).