Skewness

It is useful to describe the shape of data. It can be symmetrical or have a positive or negative skew. Data with a positive skew has a long tail in the positive direction of the horizontal axis. Data with a negative skew has....

• a long tail in the direction of the negative horizontal access

• a long tail in the direction of the positive horizontal access

Box plots can display the skew of data. The position of the median relative to the quartiles describes the skew. Match the box plots to the correct graphs below

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• 

This is the box plot from question 7. How would you describe the skewness

• The data is symmetrical

• The data is positively skewed

• The data is negatively skewed

The data in the picture:

• is negatively skewed

• positively skewed

• symmetrical

Are lines j and k skew?

• yes

• no

The data in the picture:

• is negatively skewed

• positively skewed

• symmetrical

Make notes now on the shapes of distributions and how the mean, median and mode might predict the skew of a distribution. Page 180-181 in the Statistics GCSE book will help. Let me know you have completed this task by writing a message bekow,

A positive number means positive skew. Negative number means negative skew, What do you think 0 means?

• Very negatively skewed

• Moderate negative skew

• Symmetrical data

• Moderate positive skew

• Very positive skew

Is this data positively or negatively skewed?

• Positively skewed

• Negatively skewed