Data, statistics, and probability

One-variable data distributions and measures of center and spread: practice and worksheets

Describe one-variable data with distributions, center, spread, shape, and the effect of outliers.

45 questions Foundation to advanced Grade 9

Concept overview

A useful statistical description connects a graph of the data to numerical measures. Mean and standard deviation are sensitive to outliers, while median and interquartile range are more resistant.

Key points

  • Choose mean and standard deviation for roughly symmetric data without strong outliers.
  • Choose median and IQR for skewed distributions or data with outliers.
  • Compare distributions using center, spread, shape, and unusual features.

Worked example

Adding one extremely large value usually raises the mean much more than the median, so the median better represents the typical value in that new data set.

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22foundation
9medium
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One-variable data distributions and measures of center and spread worksheet practice

Use the printable worksheet for independent practice, then check the answer key and worked explanations.

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Frequently asked questions

How should I practice One-variable data distributions and measures of center and spread?

Start with foundation questions, check each answer, and move up a level after several correct answers in a row.

How many practice questions are available?

IQClub currently has 45 published questions for this skill.

Can I use this for test preparation?

Yes. The practice reinforces school mathematics and the same reasoning used in high-school tests and entrance exams.

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