1. Please copy your homework into your assignment book
BEFORE THE BELL RINGS
Please copy your homework into your assignment book

2. Warm-up
The temperature in degrees Celsius for two weeks are given below. Use the data to make a stem-and-leaf plot.
7, 32, 34, 31, 26, 27, 23, 19, 22, 29, 30, 36, 35, 31
Temperature in Degrees Celsius
The tens digits are the stems.
Stem Leaves
0 7
1 9
The ones digits are the leaves. List the leaves from least to greatest within each row.
Key: 1|9 means 19
Title the graph and add a key.

3. Wednesday, December 7, 2016 Warm-up Frequency and Histograms Practice
Homework: Frequency and Histograms HW

4. Objectives
Describe the central tendency of a data set.
Create stem-&-leaf plots and box-&-whisker plots
Create frequency tables and histograms.
Vocabulary
mean median range
mode box-and-whisker plot
stem-and-leaf plots
frequency tables and histograms

5. The frequency of a data value is the number of times it occurs
The frequency of a data value is the number of times it occurs. A frequency table shows the frequency of each data value. If the data is divided into intervals, the table shows the frequency of each interval.

6. Example 3: Making a Frequency Table
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.

7. Step 2 Divide the data into equal intervals.
Example 3 Continued
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

8. 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.

9. Example 4: Making 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.

10. Example 4 Continued
Step 3 Title the graph
and label the horizontal and vertical scales.

11. Measures of central tendency describe how data tends toward one value
Measures of central tendency describe how data tends toward one value. You may also need to know how data is spread out across several values.
Quartiles divide a data set into four equal parts. Each quartile contains one-fourth of the values in the set. The interquartile range (IQR) is the difference between the upper and lower quartiles. The IQR represents the middle half of the data.

13. A box-and-whisker plot can be used to show how the values in a data set are distributed. The minimum is the least value that is not an outlier. The maximum is the greatest value that is not an outlier. You need five values to make a box-and-whisker plot: the minimum, first quartile, median, third quartile, and maximum.

14. Example 5: Sports Application
The number of runs scored by a softball team at 19 games is given. Use the data to make a box-and-whisker plot.
3, 8, 10, 12, 4, 9, 13, 20, 12, 15, 10, 5, 11, 5, 10, 6, 7, 6, 11
Step 1 Order the data from least to greatest.
3, 4, 5, 5, 6, 6, 7, 8, 9, 10, 10, 10, 11, 11, 12, 12, 13, 15, 20
Step 2 Identify the five needed values and determine whether there are any outliers.

15. Example 5 Continued
3, 4, 5, 5, 6, 6, 7, 8, 9, 10, 10, 10, 11, 11, 12, 12, 13, 15, 20 Q1 6 Q3 12 Q2 10
Minimum 3
Maximum 20

16. Example 5 Continued 8 16 24
Median
First quartile
Third quartile ●
Minimum
Maximum
Half of the scores are between 6 and 12 runs per game. One-fourth of the scores are between 3 and 6. The greatest score earned by this team is 20.

17. NOTES
For the following test scores: 65,67,72,72,75,82,83,
85, 86,88,91,91,93,94, 96, 97,98,99,99
Find the A) mean, B)median,
C) mode D) range
2. Use the data to create a stem and leaf plot
3. Use the data to create a frequency table and frequency histogram
4. Use the data to create a box and whisker plot