6-2 Additional Data and Outliers
Warm Up
Lesson Presentation
Problem of the Day
Lesson Quizzes
6-2 Additional Data and Outliers
Warm UpUse the numbers to answer the questions. 146, 161, 114, 178, 150, 134, 172, 131, 128
1. What is the greatest number?
2. What is the least number?
3. How can you find the median?
178
114
Order the numbers and find the middle value.
6-2 Additional Data and Outliers
Problem of the Day
Ms. Green has 6 red gloves and 10 blue gloves in a box. She closes her eyes and picks some gloves. What is the least number of gloves Ms. Green will have to pick to ensure 2 gloves of the same color?3
6-2 Additional Data and Outliers
Learn the effect of additional data and outliers.
6-2 Additional Data and Outliers
Vocabulary
outlier
6-2 Additional Data and Outliers
The mean, median, and mode may change when you add data to a data set.
6-2 Additional Data and Outliers
Additional Example 1: Sports Application
A. Find the mean, median, and mode of the data in the table.
757511Games
20022001200019991998Year
EMS Football Games Won
mean = 7 modes = 5, 7 median = 7
B. EMS also won 13 games in 1997 and 8 games in 1996. Add this data to the data in the table and find the mean, median, and mode.
mean = 8 modes = 5, 7 median = 7
The mean increased by 1, the modes remained the same, and the median remained the same.
6-2 Additional Data and Outliers
Check It Out: Example 1
A. Find the mean, median, and mode of the data in the table.
1164613Games
20022001200019991998Year
MA Basketball Games Won
mean = 8 mode = 6 median = 6
B. MA also won 15 games in 1997 and 8 games in 1996. Add this data to the data in the table and find the mean, median, and mode.
mean = 9 mode = 6 median = 8
The mean increased by 1, the mode remained the same, and the median increased by 2.
6-2 Additional Data and Outliers
An outlier is a value in a set that is very different from the other values.
6-2 Additional Data and Outliers
Additional Example 2: Application
Ms. Gray is 25 years old. She took a class with students who were 55, 52, 59, 61, 63, and 58 years old. Find the mean, median, and mode with and without Ms. Gray’s age.
mean ≈ 53.3 no mode median = 58
mean = 58 no mode median = 58.5
When you add Ms. Gray’s age, the mean decreases by about 4.7, the mode stays the same, and the median decreases by 0.5. The mean is the most affected by the outlier. The median t is closer to most of the students’ ages.
Data with Ms. Gray’s age:
Data without Ms. Gray’s age:
Ms. Grey’s age is an outlier because she is much younger than the others in the group.
Helpful Hint
6-2 Additional Data and Outliers
Check It Out: Example 2
Ms. Pink is 56 years old. She volunteered to work with people who were 25, 22, 27, 24, 26, and 23 years old. Find the mean, median, and mode with and without Ms. Pink’s age.
mean = 29 no mode median = 25
mean = 24.5 no mode median = 24.5
When you add Ms. Pink’s age, the mean increases by 4.5, the mode stays the same, and the median increases by 0.5. The mean is the most affected by the outlier. The median is closer to most of the students’ ages.
Data with Ms. Pink’s age:
Data without Ms. Pink’s age:
6-2 Additional Data and Outliers
Additional Example 3: Describing a Data Set
The Yorks are shopping for skates. They found 8 pairs of skates with the following prices:
$35, $42, $75, $40, $47, $34, $45, $40
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
Mean:
35 + 42 + 75 + 40 + 47 + 34 + 45 + 40
8
The mean is $44.75.
= 358 8
= 44.75
The mean is higher than most of the prices because of the $75 skates, and the mode doesn’t consider all of the data.
6-2 Additional Data and Outliers
Additional Example 3 Continued
The Yorks are shopping for skates. They found 8 pairs of skates with the following prices:
$35, $42, $75, $40, $47, $34, $45, $40
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
Median:
34, 35, 40, 40, 42, 45, 47, 75
40 + 42 2
The median is $41.= 82 2
= 41
The median price is the best description of the prices. Most of the skates cost about $41.
6-2 Additional Data and Outliers
Additional Example 3 Continued
The Yorks are shopping for skates. They found 8 pairs of skates with the following prices:
$35, $42, $75, $40, $47, $34, $45, $40
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
mode:
The value $40 occurs 2 times, and is more than any other value. The mode is $40.
The mode represents only 2 of the 8 values. The mode does not describe the entire data set.
6-2 Additional Data and Outliers
Mean:
17 + 15 + 3 + 12 + 13 + 16 + 19 + 19
8
The mean is $14.25.
= 114 8
= 14.25
The mean is lower than most of the prices because of the $3 glove, so the mean does not describe the data set best.
Check It Out: Example 3
The Oswalds are shopping for gloves. They found 8 pairs of gloves with the following prices:
$17, $15, $3, $12, $13, $16, $19, $19
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
6-2 Additional Data and Outliers
Median:
3, 12, 13, 15, 16, 17, 19, 19
15 + 16 2
The median is $15.50.= 31 2
= 15.5
The median price is the best description of the prices. Most of the gloves cost about $15.50.
Check It Out: Example 3 Continued
The Oswalds are shopping for gloves. They found 8 pairs of gloves with the following prices:
$17, $15, $3, $12, $13, $16, $19, $19
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
6-2 Additional Data and Outliers
mode:
The value $19 occurs 2 times, and is more than any other value. The mode is $19.
The mode represents only 2 of the 8 values. The mode does not describe the entire data set.
Check It Out: Example 3 Continued
The Oswalds are shopping for gloves. They found 8 pairs of gloves with the following prices:
$17, $15, $3, $12, $13, $16, $19, $19
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
6-2 Additional Data and Outliers
Check It Out: Example 3 Continued
The Oswalds are shopping for gloves. They found 8 pairs of gloves with the following prices:
$17, $15, $3, $12, $13, $16, $19, $19
What are the mean, median, and mode of this data set? Which statistic best describes the data set?
mean = $14.25 mode = $19 median = $15.50
The median price is the best description of the prices. Most of the gloves cost about $15.50.
The mean is lower than most of the prices because of the $3 gloves, and the mode is higher because of the two pairs costing $19.
6-2 Additional Data and Outliers
Some data sets, such as {red, blue, red}, do not contain numbers.
In this case, the only way to describe the data set is with the mode.
6-2 Additional Data and Outliers
Standard Lesson Quiz
Lesson Quizzes
Lesson Quiz for Student Response Systems
6-2 Additional Data and Outliers
Lesson Quiz
At the college bookstore, your brother buys 6 textbooks at the following prices: $21, $58, $68, $125, $36, and $140.
1. Find the mean.
2. Find the median.
3. Find the mode.
4. Your brother signs up for an additional class,
and the textbook costs $225. Recalculate the
mean, including the extra book.
$63
$74.67
none
$96.14
6-2 Additional Data and Outliers
1. The weights of 7 members of a family are 48 kg, 52 kg, 63 kg, 75 kg, 52 kg, 64 kg, and 67 kg. Identify the median.
A. 48 kg
B. 52 kg
C. 63 kg
D. 75 kg
Lesson Quiz for Student Response Systems
6-2 Additional Data and Outliers
2. The heights of seven dogs at a vet are 17 inches, 14 inches, 13 inches, 21 inches, 17 inches, 15 inches, and 22 inches. Identify the mode.
A. 17 in.
B. 16 in.
C. 15 in.
D. none
Lesson Quiz for Student Response Systems
6-2 Additional Data and Outliers
3. Lopez buys 5 collectibles at the following prices: $15, $12, $15, $13 and $16. He then buys another collectible at $75. Identify the mean with and without the sixth collectible.
A. $24.33; $14.20
B. $14.20; $13.83
C. $14.20; $12.64
D. $24.33; $29.20
Lesson Quiz for Student Response Systems