Transcript Slide 1

Statistics
Level 3 / 4
www.mathsrevision.com
Mean, Median, Mode and Range of Data Set
Class Intervals Frequency Tables
Mean from a Frequency Table
Cumulative Frequency Tables and Median
Pie-Chart
Stem and Leaf Diagrams
Scatter Graphs
Probability
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
Level 3 / 4
www.mathsrevision.com
1.
A v id e o h a s b e r e d u c e d in t h e s a le
b y 1 0 % . I t w a s £ 2 4 0 . H o w m u c h is it n o w .
2.
S im p lif y t h e r a t io 7 : 5 6
4cm
3.
3 .5 % of 6 0 0 p
4.
T id y u p t h e e x p r e s s io n
5w + 3y + 4w + 10w
5.
2
5cm
F in d t h e a r e a a n d p e r im e t e r o f t h e s h a p e . 2cm
21-Jul-15
Created by Mr. Lafferty Maths Dept.
8cm
Different Averages
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning the terms
Mean Median, Mode and
Range for a set of data.
1. Understand the differences
between the terms Mean,
Median, Mode and Range.
2. Calculate values for the
Mean, Median, Mode and
Range in a context.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Different Averages
www.mathsrevision.com
Level 3 / 4
T he M ean =
S um o f a ll th e d a ta va lue s
h o w m a n y d a ta va lue s
Find the mean of the set of data 1, 1, 1, 1, 2, 3, 26
T he M ean =
1 + 1 + 1 + 1 + 2 + 3 + 26
7
=5
Can you see that this is not the most suitable of averages since
five out of the six numbers are all below the mean of 5
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Different Averages
www.mathsrevision.com
Level 3 / 4
An average should indicate a
“measure of central tendency”
but should also indicate
what the distribution of data looks like.
This is why we have 3 different types of averages to consider
1. The Mean
2. The Median (put the data in order then find the MIDDLE value)
3. The Mode (the number that appears the most)
For the above data the Median or Mode is a better average = 1
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Different Averages
Level 3 / 4
www.mathsrevision.com
Example :
Find the mean, median, mode and range for the set of data.
Range = Highest number – Lowest Number
10, 2, 14, 1, 14, 7
M ean =
48
6
=8
M od e = 14
R a n g e = 14 - 1 = 13
21-Jul-15
M edian = 1, 2, 7, 10 , 14 , 14
M e d ia n =
Created by Mr. Lafferty Maths Dept.
7 + 10
2
=
17
2
= 8 .5
Different Averages
www.mathsrevision.com
Level 3 / 4
Now try Exercise 1
Ch17 (page 73)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
Level 3 / 4
www.mathsrevision.com
1.
F in d t h e p e r im e t e r a n d a r e a o f t h e s h a p e .
2a
6h
2.
C a lc u la t e (a ) (-3 m ) x (-4 m )
3.
( b ) (2 b ) x (3 a )
F in d t h e m e a n o f t h e d a t a s e t
3 ,5 ,5 , 7 ,1 0
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Class Intervals
Frequency Tables
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning how to
construct and interpret
Frequency Tables.
21-Jul-15
1. Be able to Construct
Frequency Table
2. Be able to Interpret
information contained in a
Frequency Table.
Created by Mr. Lafferty Maths Dept.
Class Intervals
Frequency Tables
www.mathsrevision.com
Level 3 / 4
When a set of data is large, the numbers have
to be grouped into “class intervals”.
•
Each interval must have the same number of values
•
Ideally, there should be between 6 to 10 intervals
We will now construct a Frequency Table
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Choose
suitable
Class interval
Class Intervals
Frequency Tables
www.mathsrevision.com
Level 3 / 4
Example : The test scores for a class
Class
are given below. Construct a Frequency Intervals
Table for the results.
10-19
12
15
21
71
55
56
78
21-Jul-15
23
32
12
32
76
41
17
41
40
16
75
21
19
55
51
43
34
73
20
77
69
56
42
22
47
Created by Mr. Lafferty Maths Dept.
Tally
Frequency
6
20-29
5
30-39
3
40-49
6
50-59
5
60-69
1
70-79
6
Statistics
Working Out Statistics
www.mathsrevision.com
Level 3 / 4
Now try Exercise 2
Ch17 (page 76)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
Level 3 / 4
www.mathsrevision.com
1.
A C D p la y e r h a s b e r e d u c e d in t h e s a le
b y 4 0 % . I t w a s £ 3 6 0 . H o w m u c h is it n o w .
2.
S im p lif y t h e r a t io 6 : 2 8
3.
10% of £ 22
4.
T id y u p t h e e x p r e s s io n
(- 5 ) - (- 6 ) x 2
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Frequency Tables
Working Out the Mean
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning to work
out the mean from a
Frequency Table.
21-Jul-15
1. Be able to add a third column
to a frequency table.
2. Calculate the mean from a
frequency Table.
Created by Mr. Lafferty Maths Dept.
Frequency Tables
Working Out the Mean
www.mathsrevision.com
Level 3 / 4
Example : This table shows the number No of
of coins in the pockets of some children. Coins
(c)
Adding a third column to this table
will help us find the total number of
coins and the ‘Mean’.
M ean N um b er of coins =
21-Jul-15
40
16
Freq.
(f)
fxC
1
5
5 x 1 =5
2
5
5 x 2 = 10
3
1
1x3=3
4
3
3 x 4 = 12
5
2
2 x 5 = 10
Totals
16
40
= 2 .5 c o in s
Created by Mr. Lafferty Maths Dept.
Frequency Tables
Working Out the Mean
www.mathsrevision.com
Level 3 / 4
Example : This table shows the number No of
of brothers and sisters of pupils in an Sibling
s (S)
S2 class.
Adding a third column to this table
0
will help us find the total number of
siblings and the ‘Mean’.
1
M e a n N um b e r o f sib lin g s
=
33
30
= 1.1 sib lin g s
Created by Mr. Lafferty Maths Dept.
9
Sxf
0 x 9 =0
13 1 x 13 = 13
2
6
2 x 6 = 12
3
1
3x1=3
5
1
5x1=5
Totals
21-Jul-15
Freq.
(f)
30
33
Frequency Tables
Working Out the Mean
www.mathsrevision.com
Level 3 / 4
Now try Exercise 3
Ch17 (page 78)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
Level 3 / 4
www.mathsrevision.com
1.
A C D p la y e r h a s b e r e d u c e d in t h e s a le
b y 4 0 % . I t w a s £ 3 6 0 . H o w m u c h is it n o w .
2.
S im p lif y t h e r a t io 8 6 : 2 2
3.
30% of £ 90
4.
T id y u p t h e e x p r e s s io n
(4 ) x (- 9 )  2
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Cumulative
Frequency Tables
Working Out The Median
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning how to
calculate the median
Frequency Table.
1. Be able to add a third
cumulative column to a
frequency table.
2. Be able to calculate the
median from a Cumulative
Frequency Table.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Cumulative
Frequency Tables
Working Out The Median
www.mathsrevision.com
Level 3 / 4
Example : This table shows the number
of eggs laid by a clutch of chickens each
day over a seven day period.
A third column is added to keep a
running total. This makes it easier to
get the total number of items.
You have 1 minute to come up
with a question you can easily
answer from the table.
When was the Median egg collected.
Collected on Day 5
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Day
Freq.
(f)
C. Freq.
Total so far
1
2
2
2
3
5
3
1
6
4
6
12
5
5
17
6
8
25
7
4
29
Frequency Tables
Working Out the Mean
www.mathsrevision.com
Level 3 / 4
Now try Exercise 4
Ch17 (page 80)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
Level 3 / 4
www.mathsrevision.com
1.
W h a t is t h e m e a n o f t h e n u m b e r s
16, 10, 8, 18
5
of 360
2.
C a lc u la t e
3.
C a lc u la t e 3 a x 8 a
4.
H o w m a n y d e g r e e s in
21-Jul-15
6
1
2
,
1
3
,
1
4
,
1
,
1
6 10
Created by Mr. Lafferty Maths Dept.
o f a c ir c le .
Pie Charts
Constructing Pie Charts
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning to display
data in the form of a PieChart.
21-Jul-15
1. Be able to calculate a
fraction of 360o.
2. Understand the process of
constructing a Pie Chart.
Created by Mr. Lafferty Maths Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 3 6 0  1 0 8o
x 360  54o
300
300
Squash
x 360  90o
60
30
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Total
300
R u g b y a n g le =
F o o tb a ll a n g le =
C ric k e t a n g le =
75
300
90
300
45
300
Ic e H o c k e y a n g le =
S q u a s h a n g le =
21-Jul-15
x 360  90o
x 3 6 0  1 0 8o
x 360  54o
60
300
30
300
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
x 360  72
o
108o 90
36o
54o 72o
o
x 360  36o
Created by Mr. Lafferty Maths
Dept.
Worksheet
Constructing a
Pie Chart
Favourite Sport
Rugby
75
Football
90
Cricket
45
Ice Hockey
60
Squash
30
Drawing Pie Charts
In a survey, people were asked to
indicate which one of five sports they
liked best. The information is given in
the table. Display the information in a
pie chart.
Total
21-Jul-15
Created by Mr. Lafferty Maths
Dept.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
15
90
5
90
K e y b o a rd a n g le =
x 360  140o
x 360  60o
x 360  20o
25
90
x 360  100o
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
90
90
K e y b o a rd a n g le =
x 360  140o
15
5
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
x 360  60o
x 360  20o
25
90
x 360  100o
Drum
Drawing Pie Charts
Musical Instrument
Guitar
35
Violin
10
Recorder
15
Drum
5
Keyboard
25
Total
90
G u ita r a n g le =
V io lin a n g le =
35
90
10
90
R e c o rd e r a n g le =
D ru m a n g le =
x 360  40o
90
90
K e y b o a rd a n g le =
x 360  140o
15
5
In a survey, people were asked to
indicate which one of five musical
instruments they played. The
information is given in the table.
Display the information in a pie chart.
x 360  60o
x 360  20o
25
90
x 360  100o
40o 140o
60o 100o
20o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
Drawing Pie Charts
Ice-cream Sales
Vanilla
13
Banana
22
Chocolate
28
Strawberry
57
Total
120
V a n illa a n g le =
B a n a n a a n g le =
C h o c o la te a n g le =
S tra w b e rry a n g le =
13
120
22
120
x 360  39o
x 360  66o
28
120
57
120
The information in the table shows
sales of ice-cream from an ice-cream
van one Saturday afternoon in the
summer. Display the information in a
pie chart.
x 360  84
o
x 360  171
o
84o
66o
171o
39o
Statistics
Working Out Statistics
www.mathsrevision.com
Level 3 / 4
Now try Exercise 5
Ch17 (page 81)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
Level 3 / 4
1.
W h a t is t h e m e a n o f t h e n u m b e r s
2,3, 4, 5
2.
C a lc u la t e 6 0 % o f 3 6 0
3.
C a lc u la t e 7 b x 9 b
4.
21-Jul-15
H o w m a n y d e g r e e s in
1
12
,
1
20
Created by Mr. Lafferty Maths Dept.
, o f a c ir c le .
Stem Leaf Graphs
Construction of Stem-Leaf
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning to display
data in the form of a StemLeaf Graph.
1. Be able Construct and
understand the Key-Points
of a Stem-Leaf Graph.
2. Answer questions based on
the graph.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Stem and Leaf Diagrams
Stem and leaf diagrams are a pictorial way of showing statistics
The important parts of a stem and leaf diagram are
The Title
The stem
The leaves in order starting from the stem
The number of items
The key
n = 20
Class Maths Marks
1 0 2 2 6 8
2
3 4 5 9 9
3
0 0 2 6 8 9 9
4
0 4 5
2 / 3 means a mark of 23
Stem Leaf Graphs
Construction of Stem and Leaf
www.mathsrevision.com
Level 3 / 4
A Stem – Leaf graph is another way of displaying information :
Ages
This stem and leaf graph shows
2 4 6 8
the ages of people waiting in a
3 0 1 3
queue at a post office
4 4 4 5 6 7 9
5 0 3 4 9
How many people in the queue? 20
6 1 4 5 6
How many people in their forties? 6
leaves
stem
n = 20 Key : 2 4 means 24
21-Jul-15
Created by Mr. Lafferty Maths Dept.
A group of students were asked how much pocket money they get.
The results were.
£6.60 £6.90 £6.20 £5.80 £7.40 £5.60 £6.70 £7.20
£6.10 £6.20 £5.90 £6.00 £7.20 £5.80 £6.30
Draw a Stem and Leaf diagram to show this
Pocket money
Note this gives us the same
diagram as the previous
example. This shows the
importance of the title and
key.
5
6 8 8 9
6
0 1 2 2 3 6 7 9
7
2 2 4
n = 15 6 / 2 means £6.20
Stem Leaf Graphs
Construction of Stem and Leaf
www.mathsrevision.com
Level 3 / 4
Example : Construct a stem and leaf graphs for the following
weights in (kgs) :
Weight (kgs)
1 2 2 3 5 5
2 1 3 9
3 2 2
4 0 0 1 1
12 12
40 13
57 15
54 15
55
21
13 23
55 29
15 32 32
55
40
32 40
15 41 41
21 51
40
54
23 55
41 55
29 55
51 57
12
5
stem
1 4 5 5 5 7
leaves
n = 20 Key : 2 3 means 23
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Stem and Leaf diagrams can be used to compare 2 sets of data.
To do this we draw a back to back stem and leaf diagram.
Maths marks for class 1A
9 8
0
Maths marks for class 1B
6 8 9
8 5 3
1
1 2 2 2 5 5 8
9 4 4 5 2 0
2
0 0 1 1 6 7
6 4 3 1 1 0
3
3 7 7
7 3 3
4
1
n = 20
3/2 means a mark of 32
n = 20
How many students in 1A had a mark of 31?
2
How many students in 1B had a mark of 12?
3
Which class appears to be best at Maths?
1A
Statistics
Stem Leaf
www.mathsrevision.com
Level 3 / 4
Now try Exercise 6
Ch17 (page 83)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
Level 3 / 4
1.
W h a t is t h e H C F o f 6 4 , 3 6
2.
W h a t is L C M o f 4 a n d 5
3.
C a lc u la t e 3 z x 1 2 b
4.
21-Jul-15
H o w m a n y d e g r e e s in
1
30
,
1
40
Created by Mr. Lafferty Maths Dept.
, o f a c ir c le .
Scattergraphs
Construction of Scattergraphs
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning to display
data in the form of a
scattergraph .
1. Be able to construct and
understand the Key-Points
of a scattergraph.
2. Know the term positive and
negative correlation.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
www.mathsrevision.com
Level 3 / 4
This scattergraph
shows the heights
and weights of a
sevens football team
Write down height and
Scattergraphs
weight of each player.
Construction of Scattergraph
Bob
Tim
Sam
Joe
Gary
Jim
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Dave
Scattergraphs
Construction of Scattergraph
www.mathsrevision.com
Level 3 / 4
When two quantities are strongly connected we say there is a
strong correlation between them.
Best fit line
x x
x x
x x
Strong positive
correlation
21-Jul-15
x
x x
x
x
x
Best fit line
Strong negative
correlation
Created by Mr. Lafferty Maths Dept.
Draw in the
best fit line
Scattergraphs
Construction of Scattergraph
Price
Age (£1000)
1
1
9
8
2
3
3
3
4
4
5
8
7
6
5
5
4
2
21-Jul-15
12
Is there
a correlation?
If yes, what
kind?
10
Car prices (£1000)
www.mathsrevision.com
Level 3 / 4
8
6
4
2
0
0
2
4
6
Ages (Years)
Created by Mr. Lafferty Maths Dept.
8
10
12
Scattergraphs
Construction of Scattergraphs
www.mathsrevision.com
Level 3 / 4
Now try Exercise 7
Ch17 (page 85)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Starter Questions
www.mathsrevision.com
Level 3 / 4
1.
F in d th e va lue o f x if
4x = 48
o
47
o
55
o
x
o
2.
C a lc ula te x :
3.
C h a n g e 2 3 .3 k m to m
4.
F in d th e a ve r a g e o f th e n um b e r s 1 5 , 2 5 , 2 0 ?
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Probability
Likelihood Line
www.mathsrevision.com
Level 3 / 4
Learning Intention
Success Criteria
1. We are learning how a
likelihood line helps to
understand probability.
1. Understand the term
likelihood line and probability.
2. Decide where certain
events should lie on the
likelihood line.
3. Calculate simple
probabilities.
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Probability
Likelihood Line
www.mathsrevision.com
Level 3 / 4
0
Impossible
Seeing
a butterfly
In July
21-Jul-15
0.5
Not very
likely
School
Holidays
Evens
Winning the
Lottery
Created by Mr. Lafferty Maths Dept.
1
Very
likely
Baby Born
A Boy
Certain
Go back
in time
Probability
Likelihood Line
www.mathsrevision.com
Level 3 / 4
0
Impossible
It will
Snow in winter
21-Jul-15
0.5
Not very
likely
Evens
Homework Everyone getting
Every week
100 % in test
Created by Mr. Lafferty Maths Dept.
1
Very
likely
Certain
Toss a coin Going without
That land
Food
Heads
for a year.
Statistics and Probability
www.mathsrevision.com
Level 3 / 4
Now Round the
Class Exercise 8
Ch17 (page 87)
21-Jul-15
Created by Mr. Lafferty Maths Dept.
Probability
Calculating Probability
Level 3 / 4
www.mathsrevision.com
Probability can be thought of as a simple fraction or decimal.
It always lies between 0 and 1.
0 meaning impossible ( could not happen)
1 meaning certain ( will definitely happen)
Pro b a b ility o f a n e ve n t h a ppe n in g =
21-Jul-15
n um b e r o f f a vo ura b le o utco m e s
n um b e r o f po ssib le o utco m e s
Created by Mr. Lafferty Maths Dept.
Probability
Calculating Probability
www.mathsrevision.com
Level 3 / 4
Example : A boy tossed a coin.
What is the probability that it is heads.
P( heads ) 
1
2
Example : There are 3 red and 4 green balls in a bag.
What is the probability a green ball is picked.
P( green ) 
21-Jul-15
4
34
Created by Mr. Lafferty Maths Dept.

4
7
Probability
Calculating Probability
www.mathsrevision.com
Level 3 / 4
Now try Exercise 9
Ch17 (page 87)
21-Jul-15
Created by Mr. Lafferty Maths Dept.