5-8
Center
Point Center
Point
u
OnData
The Q1 and Q3 values for this calculation method are described below.
Q1 = {value of element whose cumulative frequency ratio is greater than 1/4 and nearest to
1/4}
Q3 = {value of element whose cumulative frequency ratio is greater than 3/4 and nearest to
3/4}
The following shows an actual example of the above.
(Number of Elements: 10)
Data Value
Frequency
Cumulative
Frequency
Cumulative
Frequency Ratio
1
1
1
1/10 = 0.1
2
1
2
2/10 = 0.2
3
2
4
4/10 = 0.4
4
3
7
7/10 = 0.7
5
1
8
8/10 = 0.8
6
1
9
9/10 = 0.9
7
1
10
10/10 = 1.0
• 3 is the value of whose cumulative frequency ratio is greater than 1/4 and nearest to 1/4, so
Q1 = 3.
• 5 is the value of whose cumulative frequency ratio is greater than 3/4 and nearest to 3/4, so
Q3 = 5.
Reference Point (0.25)
Reference Point (0.75)
Median
1
2
3
4
5
6
7
9
8
= Q1
2
2
+
3
= Q3
2
7
+
8
Median
1
2
3
4
5
6
7
9
8
= Q1
2
2
+
3
= Q3
2
7
+
8
Q1
0.1
0.2
0.4
0.7
0.8
0.9
1.0
Q3
1
2
6
3
3
4
4
4
7
5
Q1
0.1
0.2
0.4
0.7
0.8
0.9
1.0
Q3
1
2
6
3
3
4
4
4
7
5
