Transcript Mean Median Mode

Mean, Median, Mode
& Range
class-VII (demo 2)
By G.D.GUPTA
TGT MATHEMATICS
K. V. ITARANA
Data- A data is a collection of numbers
gathered to give some information.
e.g. marks obtained by 10 students
in a test of class VIII , out of
20 as follows:
15,12,14,16,07,16,18,13,05,20
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Different Names
Mean
Means
Average
Arithmetic Mean
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General meaning of mean-
2, 5, 2, 1, 5
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2, 5, 2, 1, 5
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2, 5, 2, 1, 5
mean = 3
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• Mean – The mean of a
group of observation is
2, 5, 2, 1, 5
Mean = 3
?
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How to Find the Mean of a
Group of Numbers
• Step 1 – Add all the numbers.
8, 10, 12, 18, 22, 26
8+10+12+18+22+26 = 96
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• Step 2 – Divide the sum by
the number of observation.
8, 10, 12, 18, 22, 26
8+10+12+18+22+26 = 96
How many observation are there?
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How to Find the Mean of a
Group of Numbers
• Step 2 – Divide the sum by
the number of observation.
# no. of observation
16
6) 96
6
36
36
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sum
sum of all observations
Mean =
total no. of observations
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8, 10, 12, 18, 22, 26
The mean or average of these
numbers is 16.
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What is the mean of these
numbers?
2, 9, 14, 27
?
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Definition
Median
is the value of the
Middle observation.
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Definition
• Median – the value of middle
observation in a group of
numbers.
1, 3, 7, 10, 13
Median = 7
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How to Find the Median in a
Group of Numbers
• Step 1 – Arrange the observation
in ascending or descending
order.
21, 18, 24, 19, 27
18, 19, 21, 24, 27
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How to Find the Median in a
Group of Numbers
• Step 2 – Find the middle
observation.
21, 18, 24, 19, 27
18, 19, 21, 24, 27
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18, 19, 21, 24, 27
This is your median number.
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How to Find the Median in a
Group of Numbers
• Step 3 – If there are two middle
observation, find the mean of
these two numbers.
18, 19, 21, 25, 27, 28
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How to Find the Median in a
Group of Numbers
• Step 3 – If there are two middle
observation, find the median of
these two numbers.
21+ 25 = 46
median
23
2) 46
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What is the median of these
numbers?
29, 8, 4, 11, 19
?
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What is the median of these
numbers?
31, 7, 2, 12, 14, 19
?
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Definition
Mode
is the most
Popular
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Definition
• Mode – the most popular or
that which is most required.
Baseball caps are a mode today.
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Definition
• Mode – the number that
appears most frequently in a
set of numbers.
1, 1, 3, 7, 10, 13
Mode = 1
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How to Find the Mode in a
Group of Numbers
• Step 1 – Arrange the numbers in
ascending or descending order .
21, 18, 24, 19, 18
18, 18, 19, 21, 24
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How to Find the Mode in a
Group of Numbers
• Step 2 – Find the number that
is repeated the most.
21, 18, 24, 19, 18
18, 18, 19, 21, 24
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Which number is the mode?
29, 8, 4, 8, 19
4, 8, 8, 19, 29
8
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Which number is the mode?
1, 2, 2, 9, 9, 4, 9, 10
1, 2, 2, 4, 9, 9, 9, 10
9
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Which number is the mode?
22, 21, 31, 31, 21, 32,
21, 21, 22, 31, 31, 32
21and 31 are the mode
of given data.
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Definition
• Range – the difference between
the greatest and the least value
in a group of numbers.
1, 1, 3, 7, 10, 13
Range = 12
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How to Find the Range in a
Group of Numbers
• Step 1 – Arrange the numbers
in order from least to greatest.
21, 18, 24, 19, 27
18, 19, 21, 24, 27
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How to Find the Range in a
Group of Numbers
• Step 2 – Find the lowest and
highest numbers.
21, 18, 24, 19, 27
18, 19, 21, 24, 27
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How to Find the Range in a
Group of Numbers
• Step 3 – Find the difference
between these 2 numbers.
18, 19, 21, 24, 27
27 – 18 = 9
The range is 9
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What is the range?
22, 21, 27, 31, 21, 32
?
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Copyright © 2000 by Monica Yuskaitis