Statistics and Sampling Concepts

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Sample

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A part of a population. Example: If the population is 7th grade, a sample would be your math class.

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Population

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The entire group of people or objects. Example: You wanted to see what students wanted to wear for Spirit week at IMS- the population would be the entire school.

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Biased sample

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A sample that is not representative of the population and favors certain outcomes. Example: You wanted to know how the town feels about putting the new school at Bialek park. You survey people at the park.

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Unbiased sample

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A sample that is representative of an entire population. Example: You wanted to know how the town feels about putting the new school at Bialek park. You survey every 5th person that leaves SHAWs.

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Mode

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The number that appears the MOST often. Example: 5, 12, 3, 8, 8, 5, 15. The mode is 5 and 8.

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Median

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The number in the middle. Example: 5, 12, 3, 8, 8, 5, 15. Rewrite: 3, 5, 5, 8, 8, 12, 15. The median is 8 because 8 is in the middle.

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Mean

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The average, calculated by adding the numbers together and dividing by the amount of numbers. Example: 5, 12, 3, 8, 8, 5, 15. 5 + 12 + 3 + 8 + 8 + 5 + 15 = 56. 56/7 = 8. The mean is 8.

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Range

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The difference between the highest and lowest number. Example: 5, 12, 3, 8, 8, 5, 15. Max: 15, Min: 3, Range: 15 - 3 = 12. The range is 12.