Statistics How To» Blog Archive » How to find an interquartile range in statistics

Probability and statistics: Interquartile range (IQR)

Step 1: Put the numbers in order

1,2,5,6,7,9,12,15,18,19,27

Step 2: Find the median (How to find a median)

1,2,5,6,7,9,12,15,18,19,27

Step 3: Place parentheses around the numbers above and below the median.

Not necessary statistically–but it makes Q1 and Q3 easier to spot.

(1,2,5,6,7),9,(12,15,18,19,27)

Step 4: Find Q1 and Q3

Q1 can be thought of as a median in the lower half of the data, and Q3 can be thought of as a median for the upper half of data.

(1,2,5,6,7),  9, ( 12,15,18,19,27). Q1=5 and Q3=18.

Step 5. Subtract Q1 from Q3 to find the interquartile range.

18-5=13.

via Statistics How To» Blog Archive » How to find an interquartile range in statistics.

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