Statistics Class 9th Notes - Free NCERT Class 9 Maths Chapter 14 Notes - Download PDF

Statistics class 9 notes:

The Statistics is the NCERT chapter, a numerical measure of the uncertainty of diverse phenomena. It can range from 0 to 1 in positive value. The NCERT Class 9 Maths Chapter 14 Notes covers a brief outline of the chapter Statistics. The main topics covered are What is Statistics, Data, Frequency, Ungrouped data and Grouped data, Class interval, Class interval types, Graphical Representation of Data, and many more in the Statistics class 9 notes with some FAQs.

The basic equations in the chapter are also covered in the class 9 maths chapter 14 notes. All of these subjects are covered in the statistics class 9 notes pdf download. In the CBSE class 9 maths chapter 14 notes, the required derivations are not addressed. No, the notes for class 9 maths chapter 14 do not include all of the important derivations. This NCERT note provides a summary of the chapter's main ideas and equations and can be used to review Statistics.

Also, students can refer,

• NCERT Class 9 Maths Notes
• NCERT Solutions for Class 9 Maths Chapter 14 Statistics
• NCERT Exemplar Class 9 Maths Chapter 14 Solutions Statistics

NCERT Class 9 Maths Chapter 14 Notes

The Basics of Statistics

Statistics is a field of study that deals with data gathering, presentation, interpretation, and analysis.

Data

Data refers to numerical or non-numerical facts or figures gathered for a certain reason.

Data gathered from first-hand sources:

Secondary Data:

Data was gathered from a source that already had information on hand.

Frequency

In statistics, frequency refers to the number of times a specific event occurs.

Ungrouped Data

Ungrouped data is data in its most basic or unprocessed form.

There are no categories for the observations.
Grouped Data

Observations are sorted into groups in grouped data.

Class Interval

The number of classes into which a set of data is divided.

Divisions on a histogram or bar graph, for example.

Upper-class limit – lower class limit = class width

Class Intervals Are Divided Into Two Types: Regular And Irregular.
When the class intervals are identical or of the same size, it is called a regular class interval.

For example, 0-10, 10-20, 20-30.... 90-100
When the class intervals are of variable sizes, it is called an irregular class interval.

For example, 0-35, 35-45, 45-55, 55-80, 80-90, 90-95, and 95-100.

Frequency Table
A frequency table or distribution is a tabular representation of the frequency of a specific variable.
Sorting

In order to perform our activities, raw data must be sorted.

Choosing whether to sort in ascending or descending order

Ungrouped Frequency Table
When each class interval's frequency is not ordered or organised in any way.

Frequency Table With Groups

The appropriate class intervals' frequencies are organised or ordered in a specific order, either ascending or descending.

Graphical Representation of Data

Bar Graph

A bar graph is a visual representation of data in which the variable is represented by bars of uniform width drawn with equal spacing.

The variable's value is displayed on another axis, and the height of the bar represents the variable's value.

Histogram

This is similar to a bar graph, however, it is used to illustrate continuous class intervals.

Frequency Polygon
Frequency is yet another approach to describe quantitative data.

A frequency polygon is created by joining the midpoints of the upper sides of neighboring rectangles off the histogram.

Because the slope can be seen, it is a better representation (rate of increase or decrease of value).

Drawing A Frequency Polygon Without A Histogram:

Frequency polygons can also be produced without the use of histograms.

The mid-points of the class intervals utilised in the data are required for this.

Class-marks are the mid-points of the class intervals.

To determine the class mark of a class interval, add the upper and bottom limits of the class and divide by two.

As a result, Class-mark is equal to (Upper limit + Lower limit)/2.

Central Tendency Measures

Average

The average of a set of observations is the total number of observations divided by the sum of the values of all the observations.

Mean

The sum of all the values of all the observations divided by the total number of observations is the mean (or average) of a set of observations.

'X bar' is the symbol for it.

X bar =(∑X_if_i)/f_i

Mode
The most common observation is referred to as the mode.

The modal class is the class interval with the highest frequency.

Median

The importance of the middle observation.

Median =[(n+1)/2]th observation if n(number of observations) is odd.

The Median is the mean or average of the (n/2)th and [(n+1)/2]th observations when n is even.

Significance of NCERT class 9 maths chapter 14 notes

The notes for Statistics class 9th notes will help you review the chapter and acquire a sense of the important points presented.

This NCERT class 9 maths chapter 14 notes can be used to cover the core concepts of the CBSE maths syllabus in class 9 as well as for competitive exams like VITEEE, BITSAT, JEE Main, NEET , and other similar exams.

Class 9 mathematics chapter 14 notes pdf download can be used to prepare in offline mode.

NCERT solutions of class 9 subject wise

• NCERT solutions for class 9 Maths
• NCERT solutions for class 9 Science

NCERT Class 9 Exemplar Solutions for Other Subjects:

• NCERT Exemplar Class 9 Maths solutions
• NCERT Exemplar Class 9 Science solutions

NCERT Class 9 Notes Chapter wise