How is Mode calculated.

1. MODE

2. MEANING
• Derived from French
word – La Mode
which means
Fashion
• Most frequently
occurring value of a
series
• Represented by
capital letter Z

3. METHODS - INSPECTION
OR
OBSERVATION METHOD
GROUPING METHOD

4. OBEY RULES

5. STEPS - GROUPING
STEP-1
 Make 5 columns to the right of the Frequency
column
 Make 6+ 1 small columns for Analysis Table to the
right of the Grouping table.
 Make a group of 2 frequencies and add them. Write
the total against each group in column 2.
 Leave the first Frequency and then make a group of
2 frequencies. Write the total against each group in
column 3.
 Make a group of 3 frequencies and add them. Write
the total against each group in column 4.
 Leave the first Frequency and then make a group of
3 frequencies. Write the total against each group in
column 5.
 Leave the first two Frequencies and then again
make a group of 3 frequencies. Write the total
against each group in column 6.
STEP-2
Tick against the highest
frequency/frequencies in each
of the columns of the Analysis
Table.
Add the number of Ticks and
find the highest frequency.
The Class/Size corresponding
to the highest value will be the
Mode or the Modal class

6. Calculate Mode :
GROUPING ANALYSIS TABLE TOT
AL
Class No.
of
item
s
0-5 1
5-10 2
10-15 10
15-20 4
20-25 10
25-30 9
30-35 2

7. MODE in CONTINUOUS SERIES
• Where,
• L1 = lower limit of the modal class
• F1 = frequency of the modal class
• F0= frequency of the preceeding
class
• F2= frequency of the succeeding
class
• i= class interval of the modal class
Z = 𝐿1 +
𝑓1−𝑓0
2𝑓1−𝑓0−𝑓2
𝑥 𝑖

8. Calculate Mode :
Class No.
of
ite
ms
0-10 4
10-20 8
20-30 14
30-40 20
40-50 30
50-60 15
60-70 6