Box plot


Box plot
A box plot, or box and whisker diagram provides a simple graphical summary of a dataset. It is often used in exploratory data analysis to show the shape of the distribution, its central value, and its variability.The box plot is interpreted as follows: The box itself contains the middle 50% of the data. The upper edge (3rd quantile) of the box indicates the 75th percentile of the data set, and the lower edge indicates the 25th percentile (1st quantile). The line in the box indicates the median value of the data. If the median line within the box is not equidistant from the hinges, then the data is skewed. The ends of the vertical lines or "whiskers" indicate the minimum and maximum data values, unless outliers are present in which case the whiskers extend to a maximum of 1.5 times the inter-quartile range. The points outside the ends of the whiskers are outliers or suspected outliers.