Long description

An extended V-shaped diagram showing the median and quartiles. The V-shape has two additional arms, one to the left and one to the right, so the shape now resembles a capital letter M, but with the sides sloping. The numbers represented by x subscript 1, x subscript 2 and so on, ending with x subscript 15 are shown.

The shape starts on the left with x subscript 1, followed, slightly higher and to the right by x subscript 2. Following the same line are x subscript 3 and x subscript 4. At that point the V formation begins, so the next entry x subscript 5 is slightly lower down and to the right and level with x subscript 3. The same line is followed by x subscript 6, x subscript 7, which is level with x subscript 1, and x subscript 8, which is lower than x subscript 1. At x subscript 8 the direction changes again and the letters move slightly to the right and begin to rise, so x subscript 9 is level with x subscript 7. They continue to rise until x subscript 12 is reached. This is level with x subscript 4. The letters then begin to fall again, moving to the right each time, ending with x subscript 15. This is on the same horizontal level as x subscript 1.

There are three clouds, each containing words. The first contains the words ‘Lower quartile’ and has an arrow pointing to the label x subscript 4, which is at the top of the first line. To the right and at the same level is another cloud, containing the words ‘Upper quartile’, from which an arrow points to the label x subscript 12. The third cloud contains the word ‘Median’. From it an arrow points to the lowest label, x subscript 8, in the middle of the diagram.