This particular ppt is related to Research Methodology

1. Measure of
Central
Tendency

2. Average
• “An Average is a single figure that
represent whole group.” - Clark
• “An Average is the single value selected
from a group of values to represent them
in some ways”
- A.E. Waugh
• Averages are also called measure of
central tendency or measure of
location.

3. Types of Average
Types of
Average
Arithmetic
Mean
Median Mode

4. Arithmetic Mean
• Represented With X(X Bar).
• Grouping of Data
Individual Series
Discrete Series
Continuous Series

5. Arithmetic Mean
• Normal Data:
• Ex: Total No. of books issued in last five
year.
• X= ∑X
N
• Description:
X = Mean Value
∑X= Sum of All the observation
N= Total No. of Observation
Years No. of Books Issued
2019-2020 50
2018-2019 70
2017-2018 40
2016-2017 50
2015-2016 20
Total 230

6. Example: Arithmetic Mean Individual Series
• No. of visitors visited the library during a week.
No. of Days No. of
Visitors
Day 1 14
Day 2 15
Day 3 20
Day 4 23
Day 5 18

7. Example: Arithmetic
Mean Discrete
Series
Ex: No. of Books issued and no. of
Visitors/Users/ members visited the
Library during Last five years
.
No. Visitor
Visited (Xi)
No. of
Books
Issued (fi)
Xifi
20 10
12 08
15 10
18 5
19 15

8. Arithmetic Mean Continuous Series
• Example: No. of members getting books issued from a school
library during the last year as per grouped data shown below:

9. Median
• The median is that value of the variable which divides the group
into two equal parts, one part comprising of all values greater
and the other value less than the median.

10. Example: Median in Individual Series
• No. of visitors visited the library during a week.
No. of
Days
No. of
Visitors
No. of
Visitors
Day 1 14 14
Day 2 15 15
Day 3 20 18
Day 4 23 20
Day 5 18 23

11. Example: Median in Individual Series
• No. of visitors visited the library during a week.
No. of
Days
No. of
Visitors
No. of
Visitors
Day 1 14 14
Day 2 15 15
Day 3 20 18
Day 4 23 20
Day 5 18 23
Day 6 25 25

12. Example: Median in
Discrete Series
Ex: No. of Books issued and no. of
Visitors/Users/ members visited the
Library during Last five years
.
No. Visitor
Visited (Xi)
No. of
Books
Issued (fi)
c.f
12 8 8
15 10 18
18 5 23
19 16 39
20 10 49
49

14. Mode
• The value of the variable which occurs most frequently in a
distribution is called the mode.