Percentiles Percentile: the value below which a percentage of data falls. Example: You are the fourth tallest person in a group of 20 80% of people are shorter than you: That means you are at the 80th percentile . If your height is 1.85m then "1.85m" is the 80th percentile height in that group. In Order Have the data in order , so you know which values are above and below. To calculate percentiles of height: have the data in height order (sorted by height). To calculate percentiles of age: have the data in age order. And so on. Grouped Data When the data is grouped: Add up all percentages below the score, plus half the percentage at the score. Example: You Score a B! In the test 12% got D, 50% got C, 30% got B and 8% got A You got a B, so add up all the 12% that got D, all the 50% that got C, half of the 30% that got B, for a total percentile of 12% + 50% + 15% = 77% In other words you...
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