Unit 9 Lesson 5 Measures of Center-STEM AND LEAF PLOTS

Vocabulary Leaf – the last number Stem – anything to the left of the very last number (sometimes that is “0” ; sometimes it is two numbers) Key – an explanation of the stem and leaf

High temperatures for the last week: 72, 78, 87, 90, 88, 86, 87, 89 Stem Leaf = 72 degrees

Stem and Leaf Plot Here are the numbers of homeruns that Babe Ruth hit in each of his 15 years with the New York Yankees from : –54, 59, 35, 41, 46, 25, 47, 60, 54, 46, 49, 46, 41, 34, 22

StemLeaf Age of United states Presidents at their First Inauguration: (Through the 40 th presidency) Key: 5 7 means 57

Stem and Leaf Diagrams How to Draw One: 1. Put the first digits of each piece of data in numerical order down the left-hand side 2. Go through each piece of data in turn and put the remaining digits in the proper row 3. Re-draw the diagram putting the pieces of data in the right order 4. Add a key

Stem and Leaf Diagrams Remember: - Always put in a Key - Always put your data in Order Median: - to work out the median, you must find the middle value - if there are two middle values, you need the average Range: - to work out the Range, subtract the smallest number from the biggest

Stem and Leaf Diagrams The stem & leaf diagram below shows the masses in kg of some people in a lift. (a)How many people were weighed? (b)What is the range of the masses? (c)Find the median mass. Stem Leaf tens units (a) 16 people. (b) 86 – 31 = 55 kg Median is the mean of the 8 th and 9 th data values. (c) 56 kg

Using Stem-and-Leaf Plots What was the least number of cookies sold? Boxes of Girl Scout Cookies Sold by Troop boxes

Using Stem-and-Leaf Plots What was the largest number of cookies sold? Boxes of Girl Scout Cookies Sold by Troop boxes

Using Stem-and-Leaf Plots Find the median of the data Find the middle leaf… 63 boxes Boxes of Girl Scout Cookies Sold by Troop 220

Using Stem-and-Leaf Plots Find the mode of the data Look for the number that occurs most often in a row of leaves 63 boxes Boxes of Girl Scout Cookies Sold by Troop 220

Practice Pages 323 and 323 #1-16