Notes: Finding Quartiles & Interquartile range in a Data Set

Step 3: Find the 1st or lower Quartile (median of the lower half) 4, 6, 9 so.. 1st Q = 6. Step 4: Find the 3rd or upper quartile (median of the upper half) 17, 19, 21 3rd Q = 19 . Step 5: Find the interquartile range by subtracting 3rd and 1st quartile 19-6 = 13 IR = 13 . Now you try: Data Set- 10, 15, 9, 27, 3, 5, 18 ................
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