Describing and Understanding Distributions

Shape of graph?

• Skewed right

• Skewed left

• Symmetric

• Unimodal

Center and spread?

• Median and Inter-Quartile Range
• Mean and Standard Deviation
• Median and Range
• Mean and Range

Set A: 4, 7, 7, 7, 10
Set B: 4, 6, 7, 8, 10
Larger standard deviation?

• Set A
• Set B
• Both are equal.
• You can't tell.

Set A: 14, 16, 17, 18, 20
Set B: 4, 6, 7, 8, 10
Larger standard deviation?

• Set A
• Set B
• Both are equal.
• You can't tell.

5-number summary
Min: 30    Q1: 50
Median: 60    Q3: 90
Max: 170
Are there any outliers?

• There is a high outlier but no low outlier
• There is a low outlier but no high outlier
• There is both a low and high outliers
• There are no outliers

5-number summary
Min: 40    Q1: 90
Median: 105    Q3: 110
Max: 125
Are there any outliers?

• There is a high outlier but no low outlier
• There is a low outlier but no high outlier
• There is both a low and high outliers
• There are no outliers

5-number summary

Min: 30 Q1: 70

Median: 75 Q3: 90

Max: 130

Are there any outliers?

• There is a high outlier but no low outlier

• There is a low outlier but no high outlier

• There is both a low and high outlier

• There are no outliers

5-number summary
Min: 10    Q1: 40
Median: 75    Q3: 80
Max: 130
Are there any outliers?

• There is a high outlier but no low outlier
• There is a low outlier but no high outlier
• There is both a low and high outliers
• There are no outliers

• Median = 35
• Median = 36
• Median = 41
• Median = 38.5

• Range = 57

• Range = 51

• Range = 52

• Range = 50