# 6.1 Comparing data & outliers

Good morning!
Schedule:
• Learning goals
• Problem solving questions
• Review exercise
• Outliers
• Do some research!
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Slide 1: Tekstslide
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In deze les zitten 25 slides, met tekstslides.

## Onderdelen in deze les

Good morning!
Schedule:
• Learning goals
• Problem solving questions
• Review exercise
• Outliers
• Do some research!

#### Slide 1 -Tekstslide

Learning goals
At the end of these this lesson I can:
• Find the five point summary from a set of data
• Construct a boxplot from a set of data
• Find outliers from a set of data

#### Slide 2 -Tekstslide

Problem solving
What strategies did we find last time?

#### Slide 3 -Tekstslide

Problem solving
What strategies did we find last time?

- Trial and Error
- Divide problem in smaller problems/steps

31m=51m+31
155m=153m+31
152m=2
2m=30
m=15

#### Slide 7 -Tekstslide

Problem solving
Problem solving strategies:
- Trial and Error
- Divide problem in smaller problems/steps
- Realize the problem (literally DO the problem)
- Use algebraic methods

#### Slide 8 -Tekstslide

Review exercise

Key: 1 | 5 | 3 means a student from class 1 got a score of 51 and a student from class 2 got a score of 53
1. Calculate the median and range for class 1 and class 2.
2. Calculate the IQR for class 1 an class 2

#### Slide 9 -Tekstslide

Review exercise

Key: 1 | 5 | 3 means a student from class 1 got a score of 51 and a student from class 2 got a score of 53
n = 28
Middle values = 14th and 15th

Median =

Range =

270+71=70.5
9545=50
Class 1

#### Slide 10 -Tekstslide

Review exercise

Key: 1 | 5 | 3 means a student from class 1 got a score of 51 and a student from class 2 got a score of 53
n = 28
Middle values = 14th and 15th

Median =

Range =

265+66=65.5
9141=50
Class 2

#### Slide 11 -Tekstslide

Review exercise

Key: 1 | 5 | 3 means a student from class 1 got a score of 51 and a student from class 2 got a score of 53
n = 28
Q2 = median =  70.5
Q1 =
Q3 =
IQR = Q3 - Q1 = 82.5 - 62 = 20.5

Class 1
|
2(61+63)=62
2(82+83)=82.5

#### Slide 12 -Tekstslide

Review exercise

Key: 1 | 5 | 3 means a student from class 1 got a score of 51 and a student from class 2 got a score of 53
n = 28
Q2 = median =  65.5
Q1 =
Q3 =
IQR = Q3 - Q1 = 75 - 55 = 20

Class 2
|
2(55+55)=55
2(74+76)=75

#### Slide 13 -Tekstslide

Outliers
You do not count outliers in the 5 point summary (as Min or Max) !!

#### Slide 14 -Tekstslide

Outliers

<    Q1 - IQR x 1.5      Q1       Q2       Q3      Q3 +  IQR x 1.5   >
Outliers
Outliers

#### Slide 15 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46

Q1 = 21,  Q2 = 24, Q3 = 26

IQR = Q3 - Q1 = 26 - 21 = 5
Calculate if there are any outliers

#### Slide 16 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46
Q1 = 21,  Q2 = 24, Q3 = 26     IQR = 5
Minimum = Q1 - 1.5 x IQR = 21 - 1.5 x 5 = 13.5
There are NO values smaller than 13.5

Maximum = Q3 + 1.5 x IQR = 26 + 1.5 x 5 = 33.5
There is one value larger than 33.5

49 is an outlier

#### Slide 17 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46
Q1 = 21,  Q2 = 24, Q3 = 26     IQR = 5
Minimum = Q1 - 1.5 x IQR = 21 - 1.5 x 5 = 13.5

#### Slide 18 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46
Q1 = 21,  Q2 = 24, Q3 = 26     IQR = 5
Minimum = Q1 - 1.5 x IQR = 21 - 1.5 x 5 = 13.5
There are NO values smaller than 13.5

#### Slide 19 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46
Q1 = 21,  Q2 = 24, Q3 = 26     IQR = 5
Minimum = Q1 - 1.5 x IQR = 21 - 1.5 x 5 = 13.5
There are NO values smaller than 13.5

Maximum = Q3 + 1.5 x IQR = 26 + 1.5 x 5 = 33.5

#### Slide 20 -Tekstslide

Outliers
17, 18, 20, 20, 21, 22, 23, 23, 24, 24, 24, 24, 25, 26, 26, 27, 27, 30, 46
Q1 = 21,  Q2 = 24, Q3 = 26     IQR = 5
Minimum = Q1 - 1.5 x IQR = 21 - 1.5 x 5 = 13.5
There are NO values smaller than 13.5

Maximum = Q3 + 1.5 x IQR = 26 + 1.5 x 5 = 33.5
There is one value larger than 33.5

46 is an outlier

#### Slide 21 -Tekstslide

Homework for Monday 15-3-2021:
Practice 7 on p. 321-322

#### Slide 22 -Tekstslide

Social media research
Go to ManageBac and fill in the questionnaire.
You can find average screen time per app (if you don't have this option or you can give a good estimate, please do that!)
- Android: Settings > Digital Wellbeing and parental controls > Dashboard (click the Numbers next to Apps) > Click the app > Click weekly (go back one week to find your average screen time from last week)

- Iphone: Settings > Screen Timer > Show all activity > Click app to find the average

#### Slide 24 -Tekstslide

Let's do some research!
1. Go to Manageback and find the data from your survey's.
2. Choose one of the 3 categories to do your research on:
• Time spend on Physics homework
• Time spend on Math homework
• Time spend on English homework
3. Draw up a back-to-back stem-and-leaf diagram of your chosen data dividing male and female data, and a boxplot for both male and female data.
4. Calculate the five point summary and IQR for both male and female data.
5. Calculate whether there are any outliers in the data.