1. Preview
Warm Up
California Standards
Lesson Presentation

2. Warm Up
1. Order the test scores from least to greatest: 89, 93, 79, 87, 91, 88, 92.
2. Find the median of the test scores.
Find the difference.
79, 87, 88, 89, 91, 92, 93 89
3. 17 – – 7. 6
16.1
0.8
– – 23.4
3.4
166.9

3. California
Standards
SDAP1.1 Know various forms of display for data sets, including a stem-and-leaf plot or box-and-whisker plot; use the forms to display a single set of data or to compare two sets of data.
SDAP1.3 Understand the meaning of, and be able to compute, the minimum, the lower quartile, the median, the upper quartile, and the maximum of a data set.

4. Vocabulary lower quartile upper quartile box-and-whisker plot minimum
maximum

5. Litter Size 2 3 4 5 6 Number of Litters 1 8 11
The table below summarizes a cat breeder’s records for kitten litters born in a given year. You can divide the data into four equal parts using quartiles.
Litter Size 2 3 4 5 6
Number of Litters 1 8 11

6. You know that the median of a data set divides the data into a lower half and an upper half. The median of the lower half is the lower quartile, and the median of the upper half is the upper quartile.
Kitten Data
Lower half
Upper half
Lower quartile: 3 median of lower half
Median: 4
Upper quartile: 5 median of upper half

7. Additional Example 1: Finding Quartiles
Find the lower and upper quartiles for the data set.
A. 15, 83, 75, 12, 19, 74, 21
Order the values.
lower quartile: 15
upper quartile: 75

8. Additional Example 1: Finding Quartiles
Find the lower and upper quartiles for the data set.
B. 75, 61, 88, 79, 79, 99, 63, 77
Order the values.
lower quartile: = 69 2
upper quartile: = 83.5 2

9. A box-and-whisker plot shows the distribution of data
A box-and-whisker plot shows the distribution of data. The middle half of the data is represented by a “box” with a vertical line at the median. The lower fourth and upper fourth quarters are represented by “whiskers” that extend to the minimum (least) and maximum (greatest) values.
minimum
maximum
Lower quartile
Upper quartile
Median

10. Use the given data to make a box-and-whisker plot.
Additional Example 2: Making a Box-and-Whisker Plot
Use the given data to make a box-and-whisker plot.
21, 25, 15, 13, 17, 19, 19, 21
Step 1. Order the data from least to greatest. Then find the minimum, lower quartile, median, upper quartile, and maximum.
minimum: 13
maximum: 25
lower quartile: = 16 2
upper quartile: = 21 2
median: = 19 2

11. Use the given data to make a box-and-whisker plot.
Additional Example 2 Continued
Use the given data to make a box-and-whisker plot.
Step 2. Draw a number line and plot a point above each value from Step 1.

12. Use the given data to make a box-and-whisker plot.
Additional Example 2 Continued
Use the given data to make a box-and-whisker plot.
Step 3. Draw the box and whiskers.

13. Check It Out! Example 3
These box-and-whisker plots compare the point per quarter at Super Bowl XXXVII.
Quarter 1 2 3 4
Oakland 6 12
Tampa Bay 17 14
Oakland
Tampa Bay

14. Check It Out! Example 3A
A. Compare the medians and ranges.
The median for Tampa Bay is significantly greater and the range for Tampa Bay is slightly greater.
Oakland
Tampa Bay

15. Check It Out! Example 3B
B. Compare the ranges of the middle half of the data for each.
Oakland
Tampa Bay
The range of the middle half of the data is greater for Tampa Bay.

16. Lesson Quiz: Part I
Find the lower and upper quartiles for each data set.
1. 48, 52, 68, 32, 53, 47, 51
2. 3, 18, 11, 2, 7, 5, 9, 6, 13, 1, 17, 8, 0
lower = 47; upper = 53
lower = 2.5; upper = 12

17. Lesson Quiz: Part II
Use the following data for problems 3 and , 87, 98, 93, 89, 78, 94
3. Make a box-and-whisker plot.
4. What is the median and range of the data?
91; 20