services CV publications contact Value-at-Risk statistical navigator SK
Numerical variable is described using:
a) Descriptive characteristics
b) Histogram
c) Box Plot
d) Histogram combined with Box Plot
Histograms present a graphical representation of the frequency distribution of the selected variable(s) in which the columns are drawn over the class intervals and the heights of the columns are proportional to the class frequencies.
A box plot is made up of a box (a rectangle) with various lines and points added to it. The top and bottom of the box are the 25th and 75th percentiles. The length of the box is thus the interquartile range (IQR). That is, the box represents the middle 50% of the data. A line is drawn through the middle of the box at the median (the 50th percentile). The upper adjacent value is the largest observation that is less than or equal to the 75th percentile plus 1.5 times IQR. The lower adjacent value is the smallest observation that is greater than or equal to the 25th percentile minus 1.5 times IQR. The adjacent values are displayed as T-shaped lines that extend from each end of the box. Values outside the upper and lower adjacent values are called outside values.
Histogram and Box Plot can be combined into one chart.
