Five Figure Summary

1 / 18

# Five Figure Summary - PowerPoint PPT Presentation

Five Figure Summary. From List. What is to be learned. What the five figures are! How to calculate them!. Previously. Median?. Must be in order!. A proper median. Right in the middle. Not so easy. Find halfway between middle two. dodgy median. Two “in the middle”.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## Five Figure Summary

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Five Figure Summary

From List

What is to be learned
• What the five figures are!
• How to calculate them!
Previously

Median?

Must be in order!

A proper median

Right in the middle

Not so easy

Find halfway between middle two

dodgy median

Two “in the middle”

If Odd Amount of Numbers

→ There is true median

If Even

→Dodgy Median (Halfway between two middle numbers)

Amount of NumbersMedian Position

5 3rd number

7 4th number

9 5th number

116thnumber

19?

10th number

Rule

Median Position = (Amount of Numbers + 1)÷2

If 9 numbers

Median Position = (9+1) ÷ 2

= 5

i.e fifth number

If Even Data Group

Mid Point Rule

Must find mid point between two middle numbers

Find mean of two numbers

21 and 29

→ 50 ÷ 2 = 25

Common Sense

If midway between 21 and 29

21……………………………………29

8 units

25

(4 units from each)

Calculate Medians

1. 2 4 7 10 12 18 21

2. 3 6 8 9 11 18 27 31

3. 5 8 12 26 34 38 40 40

4. 34 43 45 28 31

5. 34 39 43 52 58 60

10

30

28 31 34 43 45

47.5

Quartiles

Median splits data into two “halves”

Lower quartile (Q1) is median of lower half

Upper quartile (Q3) is median of upper half

Q2 is median

Quartiles in Action

Always start by finding median

2 4 10 16 18 21

Ignore median so we can have two equal halves

Lower Half Upper Half

2 4 10 16 18 21

Q1 Q3

12

Q2

Slightly different

Q2 = 23

10 13 17 21 25 34 38 42

Will split nicely into two halves

Lower Half Upper Half

10 13 17 21 25 34 38 42

Q1 = 15

Q3 = 36

5 Figure Summary?

Final two figures are L and H

L is the lowest

H is the…………………………………………….

5 Figure Summary?

Consists of

• Median
• Lower and Upper Quartiles
• Highest and lowest numbers

Mid Point Rule

Q2

Q1 and Q3

H and L

e.g. Mid Point between 22 and 46

→68 ÷ 2 = 34

Finding The Quartiles

Median splits the data group into two “halves”

The quartiles (Q1 and Q3 are the medians

of the lower and upper half)

If there is a “true median” ignore it or you will not have equal halves!

Q2

Ex1. 2 5 8 17 19 22 28

Median

Lower HalfUpper Half

2 5 8 19 22 28

L = 2

Q1 = 5

Q2= 17

Q3 = 22

H = 28

Q1

Q3

Q2 = 18

Ex2. 2 5 8 17 19 22 28 30

Median

Lower HalfUpper Half

2 5 8 17 19 22 28 30

L = 2

Q1 = 6.5

Q2= 18

Q3 = 25

H = 30

Q3 = 25

Q1 = 6.5