1. Measures of Central Tendency
Algebra 1(B)
Statistics

2. Today’s Schedule Class Attendance / Announcements
Multiple Choice Warm-Up
Homework Check / Questions
Measures of Central Tendency Notes / Practice
Brain Break
Mean, Median, and Mode Numbers Game
Exit Slip
Begin Homework

3. Multiple Choice Warm-Up
Do your best on the following problems. Remember: try to eliminate answers you know are not correct! 1. 3. 2.

4. Homework Check / Questions
pgs. 371, 373 #9, 13-16, 34

5. Objectives Understand and apply the measures of central tendency
Recognize situations in which one measure of central tendency is more reliable than another
Vocabulary: measures of central tendency, mean, median, mode

6. What is the Mean?
Mean: the “average” of a set of data found by…
Adding the data in the set and…
Dividing that sum by the number of elements in the set.
Example:
Find the mean of the collection of numbers:
6, 5, 7, 5, 3, 4

7. Finding the Mean
A football team had offensive drives of 43, 42, 45, 44, 45, and 48 yards. Find the mean offensive drive for the team.
44.5 yards

8. Finding the Mean
The heights of the players on Oswego High School’s basketball team are 72”, 74”, 70”, 78”, 75”, and 70”. Find the mean height. Round your answer to the nearest tenth.
73.2 inches

9. Finding the Mean
The high temperatures for a 7-day week during December in Oswego were 29°, 31°, 28°, 32°, 29°, 27°, and 62°. Find the mean high temperature for the week.
34°
Is 34° a good representation of a typical week in Oswego in December. Why or why not?
Discuss this question with your partner for one minute
You will be asked to support your reasoning

10. What is the Median?
Median: the middle number of a set of data when the numbers are arranged in numerical order.
Example:
Find the median of the collection of numbers:
2, 16, 9, 10, 20, 5, 1, 10, 23 10
1, 2, 5, 9, 10, 10, 16, 20, 23

11. Finding the Median
The rainfall in the month of April in Oswego over the past 5 years has been 3.6”, 2.92”, 3.62”, 3.2”, and 3.37”. Find the median amount of rainfall in April.
3.37 inches

12. Finding the Median
Find the median of the collection of numbers:
17, 20, 2, 8, 17, 14, 20, 13, 5, 10
What should we do if there is no middle number?
Find the average of the two middle numbers!
13.5

13. What is the Mode?
Mode: the number that occurs most often in a set of data.
Hint: It will help to arrange numbers in numerical order.
Example:
Find the mode of the collection of numbers:
1, 12, 4, 5, 4, 8, 2
1, 2, 4, 4, 5, 8, 12
1, 2, 4, 4, 5, 8, 12

14. Finding the Mode
Your homework scores in math this semester have been 89%, 100%, 96%, 77%, 80%, 96%, 88%, and 83%. What is the mode of your homework scores?
96%

15. We call a set of data bimodal if it has two modes.
Finding the Mode
Find the mode of the collection of numbers:
70, 55, 60, 28, 55, 68, 70, 40
55 and 70
We call a set of data bimodal if it has two modes.
Find the mode of the collection of numbers:
12, 8, 15, 17, 5, 3, 11, 9
No mode

16. Brain Break Skate on thin ice Up for grabs
Take 2-3 minutes to get up, stretch out, talk to a neighbor, or try the following rebus puzzles…
Skate on thin ice
Up for grabs

17. Round decimals to nearest whole number!
Mean, Median, Mode Numbers Game
Instructions:
You will be divided into groups of 4. When you are sitting with your group, turn your desks to face each other.
Determine an order (who will go first, second, third, and fourth).
There will be two piles of cards: a numbers pile and a M-M-M (mean-median-mode) pile.
The first person will draw cards from the numbers pile. Each person in the group is in charge of finding the mean, median, and mode of the collection of numbers.
The same person will then draw from the M-M-M pile. This will determine the number of points Person 1 will get.
Repeat Steps 4 and 5 until everyone has gone.
Round #1  draw 3 cards
Round #2  draw 4 cards
Round #3  draw 5 cards
Round #4  draw 6 cards
Round #5  draw 7 cards
Round decimals to nearest whole number!

18. After the Game… Report your game results to a teacher
Paperclip the number cards and the M-M-M cards together
You may begin working on the homework assignment if you finish before the time limit
Homework: pgs #19-29

19. Mean, Median and Mode Song
Exit Slip
Work on this individually
Needs to be done before you leave
Begin working on the homework after you turn it in
Homework: pgs #19-29
Mean, Median and Mode Song