1. PART 2.0: ANALYSING DATA TECHNIQUES
Outcome 3.0:
Produce information in appropriate format for
decision making in an organisational context
3.1 Using data from a given business
scenario, prepare a range of graphs
using spreadsheet – line, pie, bar charts
and histograms, and draw valid
conclusions based on the information
derived

2. Graphic Presentation of a Frequency
Distribution
i. HISTOGRAM
ii. FREQUENCY POLYGON
iii. OGIVE

3. a) HISTOGRAM
• similar to bar chart but without the gaps
between the bars

4. Histogram
• class boundaries are marked on the horizontal
axis and class frequencies on the vertical axis
represented by the heights of the bars.
25
20
Frequency
15
.
10
5
0
1 2 3 4 5
Class Boundaries
.

5. Histogram
Example 1: Discrete Data: Score for correct
answer
Class
Score (x) Freq (f)
Boundaries
1–5 3 0.5 - 5.5
6 – 10 4 5.5 - 10.5
11 – 15 7 10.5 - 15.5
16 – 20 2 15.5 - 20.5
21 – 25 5 20.5 - 25.5
26 - 30 3 25.5 - 30.5

6. Histogram
Example 1: Discrete Data: Score for correct
answer Frequency of Score for the Correct Answer
No. of Students
8
7
No. of Students
6
5
4
3
2
1
0
Class
0.5 - 5.5 5.5 - 10.5 10.5 - 15.5 15.5 - 20.5 20.5 - 25.5 25.5 - 30.5
Score for Correct Answer
Boundaries

7. b) FREQUENCY POLYGON
• line segments connecting the points formed by
the intersection of the class midpoints and the
class frequency.
Frequency Polygon of Scores for the
Correct Answer
8
7
6
No.of Students
5
4
3
2
1
0
3 8 13 18 23 28
Score for Correct Answer

8. Frequency Polygon
• Add classes with ‘zero frequencies’ at both
ends of the distribution to ‘tie down’ the graph
to the horizontal scale.
Score (x) Mid-point Freq (f)
-2 0
1–5 3 3
6 – 10 8 4
11 – 15 13 7
16 – 20 18 2
21 – 25 23 5
26 - 30 28 3
33 0

9. Frequency Polygon
Frequency Polygon of Scores for the Correct
Answer
8
7
6
No.of Students
5
4
3
2
1
0
-2 3 8 13 18 23 28 33
Score for Correct Answer

10. Frequency Polygon
Frequency of Scores for the Correct Answer
8
7
6
No. of Student
5
4
3
2
1
0
-4.5 - 0.5 0.5 - 5.5 5.5 - 10.5 10.5 - 15.5 15.5 - 20.5 20.5 - 25.5 25.5 - 30.5 30.5 - 35.5
Score for Correct Answer

11. c) OGIVE (Cumulative Freq. Polygon)
• reports the number and percent of
observations that occur less than the upper
class boundary
• must convert the frequency distribution to a
cumulative frequency distribution (F)
Upper Class
Score (x) Freq (f) F
Boundaries
1–5 5.5 3 3 3
6 – 10 10.5 4 7 (3 + 4)
11 – 15 15.5 7 14 (7 + 7)
16 – 20 20.5 2 16 (14 + 2)
21 – 25 25.5 5 21 (16 + 5)
26 - 30 30.5 3 24 (21 + 3)

12. Ogive
Score (x) Freq (f) UCB F Cum.%
0 0.5 0 0.0
1–5 3 5.5 3 12.5
6 – 10 4 10.5 7 29.2
11 – 15 7 15.5 14 58.3
16 – 20 2 20.5 16 66.7
21 – 25 5 25.5 21 87.5
26 - 30 3 30.5 24 100.0

13. Ogive
Ogive of Scores for the Correct Answer
30
25
Cumulative Frequency
20
15
10
5
0
0.5 5.5 10.5 15.5 20.5 25.5 30.5
Score of Correct Answer

14. Histogram with percentages
Frequency of the Scores for Correct Answer
8 120.0
7
100.0
6
80.0
5
Frequency
4 60.0
3
40.0
2
20.0
1
0 0.0
1–5 6 – 10 11 – 15 16 – 20 21 – 25 26 - 30
Scores for Correct Answer