Measures of central tendency and dispersion
- Created by: jessicawarren
- Created on: 26-04-16 10:52
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- Measures of central tendency and dispersion
- Levels of measurement
- Nominal: Data in separate categories e.g grouping according to favourite football team
- Ordinal: Data ordered in some way e.g how much people like each football team. Difference between each item not the same, but may only be small difference between ranking of items
- Interval: Data measured using units of equal intervals e.g when counting correct answers
- Ratio: True zero point
- Measures of central tendency
- Inform us about middle values of data- averages
- Mean: Add up all data / number of items
- Median: Middle value in ordered list
- Mode: Most common data item. Modal group= group with highest frequency
- Measures of dispersion
- Range: distance between top and bottom values of data. +1
- Standard deviation: Measure of average distance between each data item above/below mean. Ignores minus values
- Levels of measurement
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