# AP Statistics Curriculum 2007 EDA Shape

(Difference between revisions)
 Revision as of 21:07, 4 June 2010 (view source)Jenny (Talk | contribs) (→Definitions)← Older edit Current revision as of 21:08, 4 June 2010 (view source)Jenny (Talk | contribs) (→Definitions) Line 10: Line 10: *** If '''mean < median''', then the distribution is left skewed *** If '''mean < median''', then the distribution is left skewed - * '''Multimodal''' distributions have two or more than one modes. Examples of multimodal distributions are: + * '''Multimodal''' distributions have two or more modes. Examples of multimodal distributions are: ** [http://en.wikipedia.org/wiki/U-quadratic_distribution U Quadratic] ** [http://en.wikipedia.org/wiki/U-quadratic_distribution U Quadratic] ** [[SOCR_EduMaterials_ModelerActivities_MixtureModel_1 | Mixture Distributions]] ** [[SOCR_EduMaterials_ModelerActivities_MixtureModel_1 | Mixture Distributions]]

## General Advance-Placement (AP) Statistics Curriculum - Measures of Shape

### Definitions

• A distribution is unimodal if it has one mode. Unimodal distributions include:
• Bell shaped distributions (symmetric, Normal)
• Skewed right or skewed left
• We can use the mean and median to help interpret the shape of a distribution. For an unimodal distribution we have these properties:
• If mean = median, then the distribution is symmetric
• If mean > median, then the distribution is right skewed
• If mean < median, then the distribution is left skewed
• Multimodal distributions have two or more modes. Examples of multimodal distributions are: ### Examples

What seems like a logical choice for the shape of the hot dog calorie data? Try looking at the histogram of the calories for the Hot-dogs dataset. ### Activities

Collect data, draw the sample histogram or dot-plot and classify the shape of the distribution accordingly. Also, if unimodal, classify symmetry (symmetric, skewed right or skewed left).

• Data collected on height of randomly sampled college students.
• Data collected on height of randomly sampled female college students.
• The salaries of all persons employed by a large university.
• The amount of time spent by students on a difficult exam.
• The grade distribution on a difficult exam.