# Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan

Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan Solutions Chapter-25. We provide step by step Solutions of Exercise / lesson-25 Statistics for ICSE Class-8  RS  Aggarwal Mathematics.

Our Solutions contain all type Questions of Exe-25 with Notes to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-8 Mathematics.

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Notes on Statistics

Exe-25 ,

### Notes on Statistics

#### Introduction to Statistics

– A study dealing with the collection, presentation and interpretation and analysis of data is called as statistics

#### Data

• Facts /figures numerical or otherwise collected for a definite purpose is called as data.
• data collected first-hand data:- Primary
• Secondary data: Data collected from a source that already had data stored

#### Frequency

– The number of times a particular instance occurs is called frequency in statistics.

#### Ungrouped data

Ungrouped data is data in its original or raw form. The observations are not classified in groups.

#### Grouped data

In grouped data, observations are organized in groups

#### Class Interval

• The size of the class into which a particular data is divided.
•    E.g divisions on a histogram or bar graph.
• Class width = upper class limit – lower class limit

#### Regular and Irregular class interval

• Regular class interval: When the class intervals are equal or of the same sizes.
• E.g 0-10, 10-20, 20-30…..
• Irregular class interval: When the class intervals are of varying sizes.
• E.g 0-35, 35-45, 45-55,

#### Frequency table

– A frequency table or distribution shows the occurrence of a particular variable in a tabular form.

#### Sorting

• Raw data needs to be sorted in order to carry out operations.-
• Sorting ⇒ ascending order or descending order

#### Ungrouped frequency table

– When the frequency of each class interval is not arranged or organised in any manner

#### Grouped frequency table

– The frequencies of the corresponding class intervals are organised or arranged in a particular manner, either ascending or descending.

### Exe-25 ,Statistics Class-8 RS Aggarwal ICSE Goyal Brothers Prakashan Solutions

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