1. Add 1 to the number of items in your data set. For example, if your data set has 23 items, add 1 to 23 to get 24. 2. Multiply the result by 3/4 to find the item in your data set
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The upper quartile, for a set of ordinal observations, is a value such that a quarter of the observations have a greater value. Similarly, the lower quartile is a value such that
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The third quartile (designated Q3) = upper quartile = cuts off highest 25% of data, or
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It's easy to find out: just plug in the sequence 1, 2, 3, 4, 5 and ask for the statistics. The first quartile comes back as 1.75. Therefore, it's picking a point between 1 and 2
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