1. DISPLAYING AND ANALYZING DATA
Chapter 11, Section 3
7th Grade Math
Mr. Glantz

2. REVIEW Frequency Table
A table that shows how often each data value occurs
Age of students
tally
frequency 11
III 3 12
IIIIIII 7 13
IIIII 5 14 II 2

3. REVIEW
Line Plot
A graph that shows the shape of a data set by stacking X’s above each data value on a number line X
X X
X X X
X X X X

4. REVIEW
Histogram
A bar graph with no spaces between the bars. The height of each bar shows the frequency of data within that interval
AGE OF STUDENTS

5. NEW INFORMATION Stem and Leaf Plot
A graph that uses the digits of each number to show the data distribution. Each data value is broken into a “stem” (digit or digits on the left) and a “leaf” (digit or digits on the right)

6. NEW INFORMATION Stem and Leaf Plot
Make a stem and leaf plot of the wind speeds (in miles per hour) recorded during a storm:
9, 14, 30, 16, 18,
25, 29, 25, 38,
34, 33
Wind Speed 1 2 3 9
4 6 8
5 5 9

7. NEW INFORMATION Stem and Leaf Plot
Create a stem-and-leaf plot for the following prices:
$1.56, $4.22, $3.78, $2.80, $4.50, $6.10, $3.40, $5.31, $3.60
Which place value will represent the “stem” in the stem-and-leaf plot?
What are the digits called that will represent the leaves of the stem-and-leaf plot?

8. NEW INFORMATION Stem and Leaf Plot
What is a double stem-and-leaf plot?
A stem-and-leaf plot that uses one set of stems for both set of leaves
For example:
Let’s compare two sets of data in a stem-and-leaf plot

9. NEW INFORMATION
The following data represents the amount of time that patients waited in the doctor’s office on Monday and Friday

10. NEW INFORMATION Waiting for the Doctor Monday Friday 1 3 9 1 2 3 4 6
Which day had the longest wait time?
How long was the longest wait time?
Does this data support this statement?
The average wait time for the doctor was about 24 minutes? 1 3 9 1 2 3 4 6
1 4
4 6 6 5
7 8 8