1. Bellwork 4/24
A students’ test scores on 6 tests were; 84, 76, 80, 64, 92, and 84.
Find the average test score.

2. Bellwork 4/24 480 480/6 = 80 The average score is 80=
480
480/6 = 80
The average score is 80

3. To construct a box and whisker plot.
Today’s Objective
To construct a box and whisker plot.
To construct a stem and leaf plot.

4. Measures of Central Tendency
There are several methods commonly used to find an average.
1.) Mean
2.) Median
3.) Mode

5. The mean is the sum of (n ) numbers divided by n.

6. Median
The median is the number in middle after the numbers have been placed in order.

7. The mode is the number that occurs most often.

8. Measures of Central Tendency
Consider the numbers: 84, 76, 80, 64, 92 and 84.
Let’s find the Mean, Median, and the Mode.

9. Mean =
480
480/6 = 80
The mean score is 80

10. Median
84, 76, 80, 64, 92, 84
64, 76, 80, 84, 84, 92
Since there is no # in the middle, we will find the median by finding the mean of the 2 #’s in the middle.

11. Median
64, 76, 80, 84, 84, 92
= 164
164/2 = 82
The median score is 82.

12. Mode
64, 76, 80, 84, 84, 92
The mode score is 84.

13. Measures of Central Tendency
64, 76, 80, 84, 84, 92
1.) Mean = 80
2.) Median = 82
3.) Mode = 84

14. Find the Mean, Median, and the Mode
22, 34, 46, 16, 34, 28
Mean = 30
Median = 31
Mode = 34

15. The median value is used to create a box & Whisker Plot.
Box & Whisker Plots
The median value is used to create a box & Whisker Plot.

16. Box & Whisker Plots 1st Quartile= median of lower half
2nd Quartile = Median
3rd Quartile = Median of upper half

17. Find the Median of the following:
310, 320, 340, 340, 420, 430, 450, 460, 490, 630, 640, 640, 670, 680, 950
Median
Median of lower half
Median of upper half

18. Box & Whisker Plots 1st Quartile= 340 2nd Quartile = 460
950
310
460
640
340
1st Quartile= 340
2nd Quartile = 460
3rd Quartile = 640

19. Box & Whisker Plots
950
310
460
640
340
Consider 460, find the percentage of numbers lower than 460.
50 %

20. Stem and Leaf Plot The Stem is the Tens digit
The Leaf is the Ones digit
Stem Leaf

21. Stem and Leaf Plot
310, 320, 340, 340, 420, 430, 450, 460, 490, 630, 640, 640, 670, 680, 950
Construct a Stem & Leaf Plot with the above data.

22. Stem and Leaf Plot
9 5
Key: 9 | 5 = 950

23. Classwork
Do Worksheet 12.6
(1-10)
Homework page 655 (1-12)