User Manual

6-12
k Calculation Methods for the Std and OnData Settings
Q1, Q3 and Med can be calculated in accordance with the Setup screen’s “Q1Q3 Type”
setting as described below.
u Std
(1) When all Frequency values are integers
With this calculation method, processing depends on whether the number of elements
n in the
population is an even number or odd number.
When the number of elements
n is an even number:
Using the center point of the total population as the reference, the population elements are
divided into two groups: a lower half group and an upper half group. Q1, Q3 and Med then
become the values described below.
Q1 = {median of the group of
2
n
items from the bottom of the population}
Q3 = {median of the group of
2
n
items from the top of the population}
Med = {
2
n
-th and
2
n
+1-th element average value}
Center Point Center Point Center Point
When the number of elements
n is an odd number:
Using the median of the total population as the reference, the population elements are divided
into two groups: a lower half group (values less than the median) and an upper half group
(values greater than the median). The median value is excluded. Q1, Q3 and Med then
become the values described below.
Q1 = {median of the group of
2
n
– 1
items from the bottom of the population}
Q3 = {median of the group of
2
n
– 1
items from the top of the population}
Med = {
2
n
+ 1
-th element}
• When
n = 1, Q1 = Q3 = Med = population center point.
2
4
+
5
=
Median
= Q1
2
2
+
3
= Q3
2
6
+
7
12345678
2
4
+
5
=
Median
= Q1
2
2
+
3
= Q3
2
6
+
7
12345678