The document contains instructions for drawing and interpreting scatter diagrams. It includes decoding a message to reveal the lesson title "Scatter Diagrams". Key terms defined are variable, scatter graph, and line of best fit. Examples of scatter diagrams show relationships between variables like age of car vs value, books marked vs pints of lager drunk, and temperature in Alaska vs money in bank. Interpreting scatter diagrams involves identifying the correlation (positive, negative, none) and using the line of best fit to make predictions from the plotted data points. Strong and weak positive correlations are distinguished by how closely the points align with the line of best fit.

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Find the title of today's lesson by decoding these coordinates:
(4,7)(2,4)(6,5)(1,8)(1,8)(1,1)(5,6) (6,8)(5,6)(6,5)(1,6)(4,4)(4,7)

2. Lesson Objective
• To be able to draw a Scatter Diagram

3. Key Words
Today’s key words
Variable - a quantity that may change in a given context
Scatter graph - uses dots to represent values for two
different numeric variables. The position of each dot on
the horizontal and vertical axis indicates values for an
individual data point.
Scatter Graphs

5. Scatter Diagrams
A Scatter Diagram is a graph of unconnected points
When drawing graphs, we must remember to do the following
things:
1. Always give the graph a title
2. Always label both axis, including correct units
3. Choose a sensible scale
4. Plot your points carefully (x first, y second)

8. Plenary Scatter Graphs
The table shows the age and value of a car.
Age of Car (Years) 2 4 6 8 10
Value of Car (£s) 7500 6250 4000 3500 2500
Complete the sentence,
As the age of the car __________,
the value of the car ___________.
Do you think this will always be
true? Explain your answer.

9. A graph to show the relationship between pints of lager
drunk and books marked
0
20
40
60
80
0 5 10 15
pints of lager
books
marked

10. A graph to showthe realtionshipbetween the number
of goals PNEconcede at the number of pupils Iput in
detention
0
5
10
15
0 1 2 3 4 5 6
goals conceded
pupils
in
detention

11. A graph to showthe relationshipbetween the
temperature in Alaska andthe money in my bank
-300
-200
-100
0
100
200
300
-30 -20 -10 0 10 20
temperature in Alaska (degrees Celcius)
money
in
ym
bank
(£)

12. Scatter Diagrams
Part Two: Interpreting Them

13. Lesson Objective
• To be able to interpret Scatter Diagrams
• To understand the terms Correlation and the Line of Best Fit

14. A graph to show the relationship between pints of lager
drunk and books marked
0
20
40
60
80
0 5 10 15
pints of lager
books
marked

15. A graph to show the relationship between pints of lager
drunk and books marked
0
20
40
60
80
0 5 10 15
pints of lager
books
marked

16. A graph to showthe realtionshipbetween the number
of goals PNEconcede at the number of pupils Iput in
detention
0
5
10
15
0 1 2 3 4 5 6
goals conceded
pupils
in
detention

17. A graph to showthe realtionshipbetween the number
of goals PNEconcede at the number of pupils Iput in
detention
0
5
10
15
0 1 2 3 4 5 6
goals conceded
pupils
in
detention

18. A graph to showthe relationshipbetween the
temperature in Alaska andthe money in my bank
-300
-200
-100
0
100
200
300
-30 -20 -10 0 10 20
temperature in Alaska (degrees Celcius)
money
in
ym
bank
(£)

19. A graph to show the relationship between the
temperature in Alaska and the money in my bank
-300
-200
-100
0
100
200
300
-30 -20 -10 0 10 20
temperature in Alaska (degrees Celcius)
money
in
ym
bank
(£)

20. • The relationship between two variables is called a Correlation
• A line of best-fit is a line which helps us to identify the type of
correlation (positive, negative, no correlation) & make predictions
• The line of best fit is drawn so that the points are evenly
distributed on either side of the line
• The closer the dots to the line, the stronger the correlation
Remember:
1. The line of best fit is a STRAIGHT LINE
2. It DOES NOT have to pass through the origin
3. It DOES NOT have to go through each point
Interpreting Scatter Diagrams

21. Correlation can be strong or weak
Strong Positive Correlation
All the points lie close to the
line of best fit
Weak Positive Correlation
The points are well spread out
from the line of best fit but
still follow the trend

22. A bit of work…
Exercise 10:2B, Page 229
Q1 - 3