1. Measures of Central Tendency
Mean, Median, Mode, Range

2. Vocabulary Hey Diddle, Diddle, the median’s the middle
You add and divide for the mean
The mode is the one, that you see the most
And the range is the difference between

3. Mean – average Median – middle Mode – most Range – difference
Vocabulary
Mean – average Median – middle Mode – most Range – difference

4. Definition
Range (difference)
the difference between the largest and smallest numbers in the list of data

5. The difference between the lowest and highest number
Range
The difference between the lowest and highest number
Test scores:
65, 73, 88, 69, 71, 78, 86, 99, 62, 77

6. Range Put in numeric order: 62, 65, 69, 71, 73, 77, 78, 86, 88, 99
Lowest number 62
Highest number 99
Range
99 – 62 = 37

7. Measures of Central Tendency
Choose your Measure!
Measures of Central Tendency

8. You have taken seven tests and earned the following grades: 80, 86, 81, 82, 85, 96, 96 Mrs. Gage is going to let you choose which measure she is going to use to determine your final grade. Would you like her to use the mean, median, mode of your test grades?
How do you choose?

9. 80, 86, 81, 82, 85, 96, 96
Put in numeric order:
80, 81, 82, 85, 86, 96, 96
Mean:
606 / 7 = 86.6
Median: 85
Mode: 96

10. Which did you choose?
MODE!!

11. You have taken 8 tests and earned the following grades: 91, 78, 80, 90, 80, 81, 88, 82 Would you like her to use the mean, median, mode of these test grades?
How do you choose?

12. 91, 78, 80, 90, 80, 81, 88, 82
Put in numeric order:
78, 80, 80, 81, 82, 88, 90, 91
Mean:
670 / 8 = 83.75
Median:
81.5
Mode: 80

13. Which did you choose?
MEAN!!

14. These are the scores from last week's geometry test:
90, 94, 53, 68, 79, 84, 87, 72, 70, 69, 65, 89, 85, 83, 72
You earned a score of 79. Your mom asks you how you did on the test compared to the rest of the class.
Calculate the three measures of the average, and decide what to tell your mom

15. Mean: 1164 / 15 = 77.6 Median: 79 Mode: 72 Numerical Order:
53, 65, 68, 69, 72, 72, 72, 79, 83, 84, 85, 89, 89, 90, 94
Mean:
1164 / 15 = 77.6
Median: 79
Mode: 72

16. What does this represent? What does this represent?
Suppose your test grades in American History are 80, 93, and 91. What grade do you need on your next test to have a 90 average?
Equation: ( X) / 4 = 90
What does this represent?
What does this represent?
What does this represent?
Missing Grade
The average you want!
How many TOTAL Grades!

17. What does this mean? 264 + x = 90 (4) • • (4) 4 264 + x = 360
Equation: ( X) / 4 = 90
264 + x = 90 4
264 + x = 360
x = 360
x =
What does this mean?
(4) •
• (4)

18. Bowling Scores: 100, 121, 105, 113, 108, x; What do I need to bowl in the last game to have an average of 112?
( x)/6 = 112
547 + x = 112 6
547 + x = 672
x = 672
x = 125
(6) •
• (6)