Mean, Mean, Median, Median, Mode Mode

& Range& Range

Outlier

• An outlier is a data item that is much higher or much lower than items in a data set.

• 1, 2, 5, 27, 3, 4

Definition

• MeanMean – the average of a group of numbers.

2, 5, 2, 1, 5Mean = 3Mean = 3

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Mean is found by evening out the numbers

2, 5, 2, 1, 5

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Mean is found by evening out the numbers

2, 5, 2, 1, 5

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Mean is found by evening out the numbers

2, 5, 2, 1, 5mean = 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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How to Find the Mean of a Group of Numbers

• Step 2 – Divide the sum by the number of addends.

8, 10, 12, 18, 22, 26

8+10+12+18+22+26 = 96 How many addends 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 addends.

6)96 sum# of addends1

636

6

63BACK

Definition

• MedianMedian – the middle number in a set of ordered numbers.

1, 3, 7, 10, 13Median = 7Median = 7

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How to Find the Median 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 Median in a Group of Numbers

• Step 2 – Find the middle number.

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 number.

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 numbers, 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 numbers, find the mean of these two numbers.

21+ 25 = 46

2) 46 23 median

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What is the median of these numbers?

16, 10, 7

10

7, 10, 16

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Definition• ModeMode – the number that

appears most often in a set of numbers.

1, 1, 3, 7, 10, 13Mode = 1Mode = 1

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How to Find the Mode in a Group of Numbers

• Step 1 – Arrange the numbers in order from least to greatest.

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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Definition• RangeRange – the difference between

the greatest and the least value in a set of numbers.

1, 1, 3, 7, 10, 13Range = 12Range = 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, 27BACK

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 = 9The range is 9

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4, 8, 8, 19, 29

What is the range?

29, 8, 4, 8, 19

29 – 4 = 25

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What is the range?

22, 21, 27, 31, 21, 32

32 – 21 = 11

21, 21, 22, 27, 31, 32

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What is the range?

31, 8, 3, 11, 19

31 – 3 = 28

3, 8, 11, 19, 31

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What is the range?

23, 7, 9, 41, 19

41 – 7 = 34

7, 9, 23, 19, 41

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17, 18, 19, 21, 24,26, 27The lower quartile (LQ) is the median of the lower half of the data.

The LQ is 18.The upper quartile (UQ) is the median of the upper half of the data. The UQ is 26.

The interquartile range is UQ-LQ

81826 BACK

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13,15,18,19,22,25

Even amounts divide in 2 equal halves.

L.Q. U.Q.

71522 Range ileInterquart

Key SkillsUse data to construct a histogram.

Jose bowled 11 games: 172, 152, 168, 157,143, 175,144, 164, 142, 172, 168.

Histogram:

TRY THIS

Bowling scores

00.5

11.5

22.5

33.5

140's 150's 160's 170's

Find the median

76, 78, 82, 87, 88, 88, 89, 90, 91, 95

88

Find the median of this segment

82

76,78, 82

1st quartile

Find the median of this segment.

90

88, 89,90

3rd quartile

76, 78, 82, 87, 88, 88, 89, 90, 91, 95

Now for the box and whisker

65 70 75 80 85 90 95

Minimum End of 1st quartile

Median End of 3rd quartile

Maximum

100 105

Find the median

142, 143, 144, 152, 157, 164, 168, 168, 172, 172 175.

164

Find the median of this segment

144

142, 143, 144

1st quartile

Find the median of this segment.

172

168, 168, 172

3rd quartile

Mean, Mean, Median, Median, Mode Mode

& Range& Range

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