# NCERT Notes for Class 11 statistics Chapter 4 Presentation of data

## Class 11 statistics Chapter 4 Presentation of data

NCERT Notes for Class 11 statistics Chapter 4 Presentation of data, (Statistics) exam are Students are taught thru NCERT books in some of state board and CBSE Schools. As the chapter involves an end, there is an exercise provided to assist students prepare for evaluation. Students need to clear up those exercises very well because the questions withinside the very last asked from those.

Sometimes, students get stuck withinside the exercises and are not able to clear up all of the questions. To assist students, solve all of the questions and maintain their studies without a doubt, we have provided step by step NCERT Notes for the students for all classes. These answers will similarly help students in scoring better marks with the assist of properly illustrated Notes as a way to similarly assist the students and answering the questions right.

## Class 11 statistics Chapter 4 Presentation of data

There are generally three forms of presentation of data:

• Textual or Descriptive presentation: In textual presentation, data are described within the text.
• Tabular presentation: In a tabular presentation, data are presented in rows (read horizontally) and columns (read vertically).
• Diagrammatic presentation

Classification used in tabulation is of four kinds: –

Qualitative

• Quantitative

• Temporal and

• Spatial

• When classification is done according to attributes, such as social status, physical status, nationality, etc., it is called qualitative classification.
• In quantitative classification, the data are classified on the basis of characteristics which are quantitative in nature, age, height, production, income, etc are quantitative characteristics.
• In Temporal classification time becomes the classifying variable and data are categorized according to time. Time may be in hours, days, weeks, months, years, etc.
• When classification is done on the basis of place, it is called spatial classification. The place may be a village/town, block, district, state, country, etc.

TABULATION OF DATA AND PARTS OF A TABLE

• A good table should essentially have the following components:-
• Table number
• Title
• Body of the Table
• Unit of Measurement
• Source
• Note

DIAGRAMMATIC PRESENTATION OF DATA

This is the third method of presenting data. There are various kinds of diagrams in common use. Amongst them the important ones are the following:

(i) Geometric diagram:- Bar diagram and pie diagram come in the category of geometric diagram.

• The bar diagrams (one dimensional diagram) are of three types: simple, multiple and component bar diagrams.
• A pie diagram is also a component diagram, but unlike a bar diagram, it is a circle broken diagram.

(ii). Frequency diagram: Data in the form of grouped frequency distributions are generally represented by frequency diagrams like histogram, frequency polygon, frequency curve and ogive.

• A histogram is a two dimensional diagram. We can have a bar diagram both for discrete and continuous variables, but histogram is drawn only for a continuous variable. Histogram also gives value of mode of the frequency distribution.
• A frequency polygon is a plane bounded by straight lines, usually four or more lines. Frequency polygon is an alternative to histogram and is also derived from histogram itself
• The frequency curve is obtained by drawing a smooth freehand curve passing through the points of the frequency polygon as closely as possible.
• Ogive is also called cumulative frequency curve. As there are two types of cumulative frequencies- ‘‘less than’’ and ‘‘more than’’. An interesting feature of the two ogives together is that their intersection point gives the median.

(iii) Arithmetic line graph: An arithmetic line graph is also called time series graph. In this graph, time is plotted along x-axis and the value of the variable (time series data) along y-axis.