Individual Series

4.4 Individual Series — Learn about unorganised vs organised individual series, arrays in ascending and descending order. CBSE Class 11 Statistics notes with interactive array visualiser.

Notes

Individual Series

Class 11 Statistics — Unorganised vs Organised Individual Series, Arrays

What is a Statistical Series?

Statistical Series
The arrangement of classified data in some logical order, like according to the size, according to the time of occurrence or according to some other measurable or non-measurable characteristics, is known as a Statistical Series.

Series Classification (based on construction)

Individual Series

• Unorganised (Raw Data)

• Organised: By Serial Number / By Order of Magnitude (Array)

Discrete Series

Frequency Array

Continuous Series

Grouped Frequency Distribution

Unorganised vs Organised Individual Series

Raw data in its original form is confusing. Let’s see how organising it makes the picture clear.

Unorganised (Raw Data)

35
40
38
17
25
45
36
29
42
22

10 observations, no particular order

Organised

1.35
2.40
3.38
4.17
5.25
6.45
7.36
8.29
9.42
10.22

When to Use Individual Series

Individual series makes data relatively easier to understand. However, if there are a large number of observations (like 500 or 1,000), individual series becomes useless. In such cases, Discrete or Continuous frequency distributions are used.

Key Takeaways

Key Takeaways

  • A statistical series arranges classified data in logical order (by size, time, or characteristics).
  • Individual series can be unorganised (raw data) or organised (by serial number or by magnitude as an array).
  • An array is data arranged in ascending or descending order, making it easy to spot the smallest and largest values.
  • Individual series is practical for small datasets but becomes useless for large datasets (500+ observations).
  • For large datasets, use discrete series (frequency array) or continuous series (grouped frequency distribution).