Histograms & Stem-Leaf Plots Kinda like bar graphs but just a lil’ different.

Stem and Leaf plot Keelan, a pro athlete, scores every time he steps on the court. His points per game throughout the season are listed below: 4, 5, 8, 13, 17, 17, 19, 20, 20, 21, 24, 28, 31, 32, 35 The “stem” is the tens place, the “leaf” is the ones place. Stem Leaf 4, 5, 8 1 3, 7, 7, 9 2 0, 0, 1, 4, 8 3 1, 2, 5

Stem and Leaf plot What was the student’s lowest grade? List of student grades. Make a stem and leaf plot. Stem Leaf 5 8 6 6, 8 7 2, 7, 7 5, 8, 9 9 1, 1, 5 What was the student’s lowest grade? What was the student’s highest grade? How many failing grades does the student have?

Team A: 65, 42, 56, 49, 58, 42, 61, 55, 45, 72 Team B: 57, 60, 48, 49, 52, 61, 58, 37, 63, 48 Team A Team B 3 7 9 5 2 2 4 8 8 9 8 6 5 5 2 7 8 5 1 6 0 1 3 2 Football State Championship Scores The tens digits are the stems. The ones digits are the leaves. Put Team A’s scores on the left side and Team B’s scores on the right. Title the graph and add a key. Key: |4|8 means 48 2|4| means 42

Theme Park Attendance by Age People 0-5 78 6-10 97 11-15 155 16-20 198 21-25 189 26-30 123 31-35 80 36-40 58 41-45 31 51-55 15 56-60 12 61-65 8 66-70 5 70+ 2

Theme Park Attendance by Age This data is Skewed. It has a tendency towards one side. In this case, it is positive skewed (leaning left) Negative skew leans right.

Characteristics of Frequency Tables and Histograms Range of values split evenly.(Ex: goes up by 5 each time 1-5, 6-10…) Histograms: Like a bar graph. The bars are touching.

Frequency of landing heads after 20 coin flips 0-2 3-5 1 6-8 5 9-11 8 12-14 4 15-17 2 18-20

Frequency of landing heads after 20 coin flips This data is distributed normally. A Normal distribution. Normal distribution is centered

Number of Customers in a Restaurant During the Day Time # of Customers 11:00-12:00 15 12:00-1:00 35 1:00-2:00 51 2:00-3:00 36 3:00-4:00 13 4:00-5:00 5:00-6:00 24 6:00-7:00 37 7:00-8:00 57 8:00-9:00 31 9:00-10:00 18 10:00-11:00 6

Number of Customers in a Restaurant During the Day This is a bimodal distribution. It has two peaks.

ON YOUR OWN PAPER

How to make Frequency Tables The numbers of students enrolled in Western Civilization classes at a university are given below. Use the data to make a frequency table with intervals. 12, 22, 18, 9, 25, 31, 28, 19, 22, 27, 32, 14 Step 1: Identify the least and greatest values. The least value is 9. The greatest value is 32.

How to make Frequency Tables Step 2: Divide the data into equal intervals. For this data set, use an interval of 10. Enrollment in Western Civilization Classes Step 3 List the intervals in the first column of the table. Count the number of data values in each interval and list the count in the last column. Give the table a title. Number Enrolled Frequency 1 – 10 1 11 – 20 4 21 – 30 5 31 – 40 2

How to make a Histogram A histogram is a bar graph used to display the frequency of data divided into equal intervals. The bars must be of equal width and should touch, but not overlap.

How to make a Histogram Use the frequency table in Example 2 to make a histogram. Step 1: Use the scale and interval from the frequency table. Enrollment in Western Civilization Classes Number Enrolled Frequency 1 – 10 1 11 – 20 4 21 – 30 5 31 – 40 2 Step 2: Draw a bar for the number of classes in each interval. All bars should be the same width. The bars should touch, but not overlap.

Pick a number between 1-50 Create a frequency Table Stem Leaf 1 2 3 4 1 2 3 4 5 Create a frequency Table Number Frequency 0-9 10-19 20-29 30-39 40-50

Making a Histogram from a frequency Table

Pennies Year Age 2017 2012 5 2007 10 2002 15 1997 20 1992 25 1987 30 1982 35 1977 40 1972 45 1967 50 Make a list of the ages of your pennies. Create a stem and leaf plot of the ages. Create a frequency table of the ages. Create a histogram of the ages.