Stem – and – Leaf Plots

What is a Stem – and – Leaf Plot?

• A Graph that shows groups of data arranged by place value• The stems represent multiples of 10• The leaves represent the ones placeExample: Students’ Quiz Scores

Key: 7|6 = 76

Stem Leaves 7 8 9 10

6 6 8 80 2 4 4 82 4 6 6 60 0

Stem–and–Leaf Plot is excellent tool in finding:

• Mean • Median• Mode • Range

• Mean – the average; add the numbers up and divide by the # of pieces of data

• Median – the number in the middle; put the numbers in order from least to greatest

• Mode – the number that appears most often• Range – the difference between the greatest number

and the lowest number

Double Stem-and-Leaf Plot

• Compares two sets of related data• Example: Mr. Grayson’s Class Test Scores

Key: 7|2 = 72

Class 1 Class 2 Leaves Stem Leaves 6 6 2 2 8 8 8 8 4 4 4 0 6 6 6 2 2 2 0 0

7 8 9 10

2 2 2 6 6 0 0 0 4 2 2 2 2 6 6 6 0 0 0 0

Examples:

Draw a Stem-and-Leaf Plot and find:Mean, Median, Mode, and Range of the data.

Example 1: Test Scores: 76,76,78,78,80,82,84,84,88,92,94,

96,96,96,100,100Albert Pujols’ Homeruns: 37, 34, 43, 46, 41, 49,

32, 37, 47, 42, 37