1. Frequency Tables and Histograms
Organize and display data
Using tallies and a graph similar to a bar graph

2. Frequency Table Use intervals – this will be the labels for the x axis
About 5 intervals is good, give or take one, do not want too many or too little
Find the range – use range to determine how many intervals
Divide by number of intervals, round answer up
Use tallies to count how many times you have data in the interval
Add up the tallies to get the frequency

3. Histogram This looks like the frequency table on its side
X-axis should be the intervals, not spaces between them
Y-axis is the frequency
Draw bars for each interval to represent the frequency

4. Given the data make a frequency table and a histogram
5, 12, 22, 15, 17, 13, 25, 34, 7, 9, 12, 32, 12, 15, 18
Range is 34-5=29
29/ 5=5.8 round up to 6
Dividing by 5 tells us how many numbers to use in each interval
The 6 tells us how many intervals we could have
Age
Frequency
5-9 3
10-14 4
15-19
20-24 1
25-29
30-34 2

6. Stem and Leaf Plots Stem – the tens place Leaf – the ones place
A stem-and-leaf plot arranges data by dividing each data value into two parts:
a leaf (the last digit), and a stem (the digit or digits other than the last digit).
Stem – the tens place
Leaf – the ones place

7. Example of Stem and Leaf
55, 82, 90, 113, 100, 90, 93, 68, 66,
108, 116, 56, 85, 89, 102, 103
Step 1: List the stems.
The least value is 55, the greatest value is 116.
List stems from 5 to 11. Do not omit any stems.
Step 2: List the leaves.
For each stem, write the ones digit from least
to greatest.
Step 3: Write a key explaining one value.

8. Make a Stem and Leaf Plot
Make a Frequency table and a Histogram