Page 16 - Basic Statistics
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LOF LIF UIF UOF
Q1 Q2 Q3
Figure 1.9 Boxplot Diagram
Description :
Q1 = First quartile
Q2 = Second quartile
Q3 = Third quartile
LOF = lower outer fence limit
= Q1 – 3 (Q3 - Q1)
LIF = lower inner fence
= Q1 - 3/2 (Q3 - Q1)
UIF = upper inner fence
= Q3 + 3/2 (Q3 - Q1)
UOF = upper outer fence
= Q3 + 3 (Q3 - Q1)
Worked Example 1.1:
Draw a boxplot diagram of the following data
21 40 42 50 60 64 72 78
80 84 85 86 86 90 90 90
92 98 100 114 120 140 160 215
Worked solution:
Q1 lies at 6.25th observation, so that
Q1 = 64 + 0.25 (72 - 64) = 66
~~* CHAPTER 1 PRESENTATION OF DATA *~~
