Course: 7th Grade Math
Student Objective
(Obj. 5b)
TSW… learn the affects of outliers on mean, median, mode and range.
DETAIL LESSON PLAN
Wednesday, March 21 / Thursday, March 22
Lesson
1-10 Median, Mean, Mode, and Range (Textbook Pages: 53-58)
Extra Resources
Thinking Map Flow Map (Finding the affect of an outlier.)
Homework
Short test tomorrow on Mean, Median, Mode, and Range. Complete study guide (5 problems).
Last Night’s Homework
None
Bellwork
MCT (A) Problem #’s 5, 6, 7, 9, 11
Prior Knowledge
 Review bellwork.
 Review homework.
 Last class, we learned that the mean, median, and mode are 3 different ways you can find the center of a set of data.
 The fancy way of saying the same thing is that the mean, median, and mode are “Measures of Central Tendency.”
 Does anyone remember another useful way to analyze data, but it does not show the center of your data? Range
Anticipatory Set
 Today, we are going to learn what an Outlier is and how it affects your Mean, Median, Mode, and Range.
 What is an outlier and how can we use an outlier in the real world?
 Display “Sleep is Important” real world example. (PowerPoint)
Teacher Input
 Pass out Student Notes.
 Demonstrate how to pick out an outlier.
 Work through “sleep is important” real world problem pertaining to the affects of an outlier on mean, median, mode, or range.
 Allow students to work you-try problem independently.
 Classwork:
Berg Created Practice Sheet (4 problems)
 Extra Practice: Fast Finisher Sheet (7 problems)
Students may begin working on their study guide
PH 3-3 if needed
Assessment
Observation and questioning. Students will take a short test on objective 5b next class period.
Closure
1. What is an outlier? A number that is way different from the other numbers in a data set.
2. Will you always have an outlier in a dataset? No
3. How would you determine the affects of on outlier on the mean?
Determine the mean without the outlier, then with the outlier. You can then find the difference to see how much the mean was
lowered or raised.
4. Do you think an outlier would affect the most: Mean, Median, or Mode Mean
Student Notes
Lesson 1-10 Outliers & Central Tendency
Textbook Pages 53 - 58
 An outlier is a number that is quite different from the other values in a data set.
 A set of data may or may not have an outlier.
 An outlier will throw off your mean more than it will your median and mode!
 So… if you are trying to find the center of your data and your dataset has an outlier it would
be best not to use your mean. It would not be accurate.
To find the affect of an outlier on mean, median, mode, or range:
Randi recorded the number of hours she worked each week during July and August.
18 22 16 20 44 19 21 16
1. Which value is the outlier? _______
2. What is the mean of the data set without the outlier (rounded to nearest tenth)? _______
3. What is the mean of the data set with the outlier? _______
4. How does the outlier affect the mean of this dataset?
Increases or decreases by:
5. What is the median of the dataset without the outlier? _______
6. What is the median of the dataset with the outlier? _______
7. How does the outlier affect the median of this dataset?
Increases or decreases by only:
Name: _______________________
Period: _________
Date: ___________
Outliers
1) The following list shows how many raffle tickets Lisa sold each week for 5 weeks.
25, 29, 31, 26, 34
Classwork
If she sells 77 tickets in the sixth week, how will that affect her mean?
A.
B.
C.
D.
will not change
increase between 5 and 10
decrease between 0 and 5
increase between 10 and 30
2) In the past four days, Hillary has practiced the clarinet for 45, 60, 75, and 60 minutes. If she does not
practice at all tomorrow, how will the median of her practice times change?
A.
B.
C.
D.
will not change
decrease of more than 10
decrease between 5 and 10
increase of more than 1
Mean, Median, Mode, and
Range
3) The following table shows the names and ages of the nine members of the Stevens family.
Name
Age
What is the mode age of the Stevens family?
Tammy
24
A. 29
Michael
27
B. 30
Trista
29
C. 31
Gary
29
D. 34
Pat
29
Britney
31
Geoff
31
4) Which set has a range of 33.
Shelly
52
A. 5, 35, 1, 3
Ken
54
B. 39, 35, 40, 38, 35
C. 50, 17, 38
D. 97, 99, 2, 4, 100, 1, 98, 3, 35
Name: ___Answer Key______
Period: _________
Date: ___________
Outliers
1) The following list shows how many raffle tickets Lisa sold each week for 5 weeks.
25, 29, 31, 26, 34
Classwork
If she sells 77 tickets in the sixth week, how will that affect her mean?
A.
B.
C.
D.
will not change
increase between 5 and 10
decrease between 0 and 5
increase between 10 and 30
Explanation: w/o 25 + 29 + 31 + 26 + 34 = 145
w 25 + 29 + 31 + 26 + 34 + 77 = 222
145 5 = 29 mean
222 6 = 37 mean
Increased by 8
2) In the past four days, Hillary has practiced the clarinet for 45, 60, 75, and 60 minutes. If she does not
practice at all tomorrow, how will the median of her practice times change? MCT (B)
A.
B.
C.
D.
will not change
decrease of more than 10
decrease between 5 and 10
increase of more than 1
Explanation: w/o
45 60 60 75
w 0 45 60 60 75
60 + 60 = 120
60 median
No change!
120
2 = 60 median
Mean, Median, Mode, and Range
3) The following table shows the names and ages of the nine members of the Stevens family. MCT (B)
Name
Age
What is the mode age of the Stevens family?
Tammy
24
A. 29
Michael
27
B. 30
Trista
29
C. 31
Gary
29
D. 34
Pat
29
Britney
31
Geoff
31
4) Which set has a range of 33. MCT (A)
Shelly
52
A. 5, 35, 1, 3
35 – 1 = 34
Ken
54
B. 39, 35, 40, 38, 35
40 – 35 = 5
C. 50, 17, 38
50 – 17 = 33
D. 97, 99, 2, 4, 100, 1, 98, 3, 35
100 – 1 = 99
Name: _____________________________
Date: _________
Period: _________
Mean, Median, Mode, Range
Study Guide
“Test Next Class!”
Use a calculator to answer the following questions.
1. Complete the following using the following word bank:
Most
Mean =
Median =
Mode =
Range =
Middle
Biggest – Smallest
Average
_________________________
_________________________
_________________________
_________________________
2. The world’s largest body of freshwater is formed by the Great Lakes of North America. Use the table of
depths to find the following statistics. Please round to the nearest tenth where necessary.
Lake
Superior
Michigan
Huron
Erie
Ontario
Mean:
Median:
Mode:
Range:
Depth (in feet)
1,333
923
750
210
802
____________
____________
____________
____________
3. Which data set has a mode of 72?
A. 3, 16, 2, 2, 75, 23, 6, 72
B. 46, 54, 12, 39
C. 81, 24, 24, 3, 100, 64, 72, 65, 44, 72, 17
D. 5, 7, 10, 72, 89, 91, 97
4) In her last five basketball games, Joan has scored 10, 6, 3, 7, and 8 points.
If she scores 22 points in her next game, how will the mean of her points scored change?
A.
B.
C.
D.
decrease of less than 5
increase between 0.1 and 3
increase between 3.1 and 6
increase of more than 6
5) Looking at question number 4, how will the median change?
The median will increase by: ___________
Name: ____Answer Key_____________
Date: _________
Period: _________
Mean, Median, Mode, Range
Study Guide
“Test Next Class!”
Use a calculator to answer the following questions.
1. Complete the following using the following word bank:
Most
Mean =
Median =
Mode =
Range =
Middle
Biggest – Smallest
_________________________
_________________________
_________________________
_________________________
Average
Average
Middle
Most
Biggest – Smallest
2. The world’s largest body of freshwater is formed by the Great Lakes of North America. Use the table of
depths to find the following statistics. Please round to the nearest tenth where necessary.
Lake
Superior
Michigan
Huron
Erie
Ontario
Mean:
Median:
Mode:
Range:
____803.6_______
____802________
____none_______
____1,123_______
Depth (in feet)
1,333
923
750
210
802
4018 5
210 750 802 923 1333
1333
210
3. Which data set has a mode of 72?
A. 3, 16, 2, 2, 75, 23, 6, 72
B. 46, 54, 12, 39
C. 81, 24, 24, 3, 100, 64, 72, 65, 44, 72, 17
D. 5, 7, 10, 72, 89, 91, 97
4) In her last five basketball games, Joan has scored 10, 6, 3, 7, and 8 points.
If she scores 22 points in her next game, how will the mean of her points scored change?
A.
B.
C.
D.
decrease of less than 5
increase between 0.1 and 3
increase between 3.1 and 6
increase of more than 6
w/o 10 + 6 + 3 + 7 + 8 = 34
w 10 + 6 + 3 + 7 + 8 + 22
5) Looking at question number 4, how will the median change
The median will increase by: ___.5______
34 5
= 6.8
56 6 = 9.3333 = 9.3
9.3 – 6.8 = 2.5 increase
w/o 3, 6, 7, 8, 10
w 3, 6, 7, 8, 10, 22
=7
= 7.5