A

**stem-and-leaf plot** is a two column data display

which shows the

frequency of values in a data set.

Typically, the last digit of the value is in the leaf column, and the

preceding digits are shown in the same row in the stem column.

The stem-and-leaf plot represents values in the twenties, thirties, forties, fifties, and sixties.

The first row, with a 2 in the stem column, represents values in the twenties: 25, 27, 28, 28, and 29.

The second row, with a 3 in the stem column, represents values in the thirties: 30, 31, 33, 36, 37, and 37.

The third row, with a 4 in the stem column, represents values in the forties: 41, 42, 42, 43, and 44.

The fourth row, with a 5 in the stem column, represents values in the fifties: 52, 53, and 55.

The last row, with a 6 in the stem column, represents values in the sixties: 60 and 61.

The oldest teacher is 61. The youngest teacher is 25.

Find the difference.