ABCDEFGHIJKLMNOPQRSTUVWXYZ
1
2
Basic Statistics
3
4
1
Suppose these are the key sectors that contribute to a country's GDP
5
6
SectorContribution to GDP
(in billions of US$)
7
Agriculture38
8
Manufacturing24
9
Trade & Commerce20
10
Financial Services18
11
ICT12
12
Real Estate10
13
Extractives (Oil & Mining)120
14
15
Summary StatisticsStatisticInterpretation
16
Mean/Average35Suggests that each sector contributes “about US$ 35 billion” — but that’s misleading because one huge sector (Extractives) skews the figure upward.
17
Median/ Middle Value20Arrange these in order (ascending/descending). Half of the sectors contribute less than 20, half contribute more. This gives a truer sense of the “typical” sector’s size.
18
19
NB: In skewed data — like income distribution or sector contributions — median is a better measure of central tendency than mean.
20
21
22
2
Disease Prevalence (Respiratory Cases in Africa)
23
Country in Africa# of Reported Cases
24
Ghana5
25
South Africa6
26
Belize6
27
Poland5
28
Malaysia5
29
United States50
30
31
32
StatisticFormula (conceptual)ValueInterpretation
33
Mean(5+6+6+5+5+50)/612.8Misleading — it looks like every community has ~13 cases, but 5 out of 6 have fewer than 7!
34
MedianMiddle of ordered list5.5Better — shows that the typical community has around 5 or 6 cases.
35
ModeMost frequent value5Best — tells us that 5 cases is the most common situation.
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100