Box Plots
Main Concept
A boxplot is a graph that provides a graphical summary of the central tendency and the variability of a sample of data. Box plots show the mean and median of a data sample as well as the first and third quartiles. Box plots can also have lines that extend vertically from the boxes, known as whiskers, that indicate minimum and maximum values. Box plots that include the whiskers are referred to as box-and-whisker diagrams.
A box plot shows:
Maximum value - the largest value in a data sample.
Upper quartile (Q3) - the third quartile, which splits the highest 25% of the data.
Median - also known as the second quartile, the median splits the data sample in half.
Mean - the average value of the sample.
Lower quartile (Q1) - the first quartile, which splits the lowest 25% of the data.
Minimum value - the smallest value in a data sample.
Box Plot
It is important to note that the "boxed" area represents 50% of the sample population, namely the points between the first and third quartiles. As such, box plots are useful for observing the spread of the distribution by observing the boxed area. For example, a smaller boxed area can represent a smaller variability in the sample, meaning that most of the observations may be clustered around the center of the sample. This makes the box plot a good tool for visually comparing multiple different data sets.
Choose numbers between 1 and 102050100
Mean:
Median:
Maximum value:
Third quartile:
First quartile:
Minimum value:
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