Download Average of data

Average of data
Mode
Mean
Median
Which is the best class
A
Class A
35
30
25
20
15
10
5
0
insuficient
suficient
notable
excel.lent
OR
class B
Class B
16
14
12
10
8
6
4
2
0
insuficient
suficient
notable
excel.lent
Class A
0,50
0,40
0,30
0,20
0,10
0,00
insuficient
suficient
notable
excel.lent
notable
excel.lent
Class B
0,60
Frequency per unit
Frequency per unit
0,60
0,50
0,40
0,30
0,20
0,10
0,00
insuficient
suficient
• What has it changed?
• It is easier to discuss
which is the best?
• How many Suficient
are in each class ?
• Do we have enough
information to find out
which is the best?
• Can we work out the Mean for each class?
Class B
Frequency per unit
0,60
0,50
0,40
0,30
0,20
0,10
0,00
4
5
7,5
9
Class A
Frequency per unit
0,60
0,50
0,40
0,30
0,20
0,10
0,00
4
5
7,5
9
• Class A
4x0,25+5x0,50+
+7,5x0,13+9x0,12 =
=5,5
• Class B
4x0,50+5x0,30+
+7,5x0,07+9x0,13=
=5,2
Which is the best ?
Class B
Class A
0,60
Frequency per unit
Frequency per unit
0,60
0,50
0,40
0,30
0,20
0,10
0,50
0,40
0,30
0,20
0,10
0,00
0,00
4
5
7,5
XA  5,55
9
4
5
7,5
XB  5,2
9
Median
Is the middle value when the
values are put in order of size
EXAMPLE
A football team scored :
2, 4, 0, 1, 3, 3, 3, 6, 2, 4
goals in the first 10 matches
Let’s put in order of size, as there
are 10 values, we get the 5th and
the 6th, and (3+3)/2=3
0, 1, 2, 2,
3, 3
3, 4, 4, 6
If there were 11 values:
0, 1, 2, 2, 2, 3, 3, 3, 4, 4, 6
The median will be the 6th value:
0, 1, 2, 2, 2
3
3, 3, 4, 4, 6
Quick test
Charlotte made this table for the number
of minutes students were late
Number of minutes 0
late (x)
Frequency
1
2
3
4
Total
10 4
6
3
2
25
Calculate:
•
•
•
•
The mean
The median
The mode
The range
•
•
•
•
The mean is
The median is
The mode is
The range is
He loves me
Martina and her friend Sara both fancy the same
boy in their class.
In their passionate state, they’ve been picking
daisies in the park.
Sara has challenged Martina whoever has more
petals on their daisies on average can ask the
boy out.
He loves me
www.outfordemocracy.org/arch/2007_05.html
Standard deviation
The most spread:
Class D
Standard Deviation 3,55
then,
Class C, 2,87
1
2
3
4
5
6
7
8
9
10
12
10
8
6
4
2
0
1
2
3
4
5
6
7
8
9
10
Class B,
Standard deviation,2,87
And, the lowest
spread,
12
0
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
12
10
8
Class A,
Standard Deviation, 2,16
6
4
2
0