Skewness and Symmetrical

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

The data in the picture:

• is negatively skewed

• positively skewed

• symmetrical

The data in the picture:

• is negatively skewed

• positively skewed

• symmetrical

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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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,

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

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

Describe the graph

• skewed right

• skewed left

• normal/symmetrical

Describe the graph

• skewed right

• skewed left