MODIFIED BOX AND WHISKER PLOT HOW TO

Of graph he should create, that might be a littleīit more straightforward than the actual creation of the Should he create? So the answer of what kind That people traveled or that people travel. The spread of distances and the median distance Spread of the distances- this is a key word. There are two potential outliers in distribution A.Wants to find out more about where his patronsįollowing distances traveled. According to the definition used by the function in R software, all values higher than Q3 + 1.5 x (Q3 - Q1) = 0.32 + 1.5 x 0.30 = 0.77 are outside the right whisker and indicated by a circle. The distribution C is negatively skewed because the whisker and half-box are longer on the left side of the median than on the right side.Īll three distributions include potential outliers. The centre of distribution C is the highest of the three distributions (median is 0.88).

It’s the most concentrated distribution because the interquartile range is 0.21, compared to 0.30 for distribution A and 0.26 for distribution C.

Distribution B is approximately symmetric, because both half-boxes are almost the same length (0.11 on the left side and 0.10 on the right side).

The distribution is positively skewed, because the whisker and half-box are longer on the right side of the median than on the left side.

The centre of distribution A is the lowest of the three distributions (median is 0.11).

The information is grouped by Measurement (appearing as row headers), Distribution A, Distribution B and Distribution C (appearing as column headers). This table displays the results of Data table for chart 4.5.2.1. Example 1 – Comparison of three box and whisker plots Data points that are outside this interval are represented as points on the graph and considered potential outliers. That is, the whisker reaches the value that is the furthest from the centre while still being inside a distance of 1.5 times the interquartile range from the lower or upper quartile.

The box and whisker plot can be presented horizontally, like in figure 4.5.2.1, or vertically.Ī variation of the box and whisker plot restricts the length of the whiskers to a maximum of 1.5 times the interquartile range.

The graph is usually presented with an axis that indicates the values (not shown on figure 4.5.2.1).

The whiskers are the two lines outside the box, that go from the minimum to the lower quartile (the start of the box) and then from the upper quartile (the end of the box) to the maximum.

Sometimes, the mean is also indicated by a dot or a cross on the box plot.

The vertical line that split the box in two is the median.

The box covers the interquartile interval, where 50% of the data is found.

The left and right sides of the box are the lower and upper quartiles.

The figure shows the shape of a box and whisker plot and the position of the minimum, lower quartile, median, upper quartile and maximum.

MODIFIED BOX AND WHISKER PLOT HOW TO

A box plot is ideal for comparing distributions because the centre, spread and overall range are immediately apparent.įigure 4.5.2.1 shows how to build the box and whisker plot from the five-number summary. It doesn’t show the distribution in as much detail as histogram does, but it’s especially useful for indicating whether a distribution is skewed and whether there are potential unusual observations (outliers) in the data set. The box and whisker plot, sometimes simply called the box plot, is a type of graph that help visualize the five-number summary.

Modified box and whisker plot