A box and whisker plot shows the minimum value, first quartile, median, third quartile and maximum value of a data set.

The x in the box represents the mean (also 8 in this example).

The bottom line of the box represents the median of the bottom half or 1st quartile (4).

The top line of the box represents the median of the top half or 3rd quartile (12).

The whiskers (vertical lines) extend from the ends of the box to the minimum value (2) and maximum value (15).

The 1st quartile (Q 1 ) is the median of the first half.

A data point is considered an outlier if it exceeds a distance of 1.5 times the IQR below the 1st quartile (Q 1 - 1.5 IQR 2 - 1.5 13 -17.5) or 1.5 times the IQR above the 3rd quartile (Q 3 1.5 IQR 15 1.5 13 34.5).

Therefore, in this example, 35 is considered an outlier.

As a result, the top whisker extends to the largest value (18) within this range.

This function interpolates between two values to calculate a quartile.

You can verify this number by using the QUARTILE.EXC function or looking at the box and whisker plot.

This makes sense, the median is the average of the middle two numbers.

Again, you can verify this number by using the QUARTILE.EXC function or looking at the box and whisker plot.

Excel For Mac 15.33 Box And Whisker