Statistics & Probability : Understanding Statistics

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Understanding Statistics

what you'll learn...

overview

In this page, A simple introduction to what is data and what we learn in statistics is given with examples.

• Collection of information is called "data".

• Statistics is about collection, representation, and analyzing data.

collection of several numbers

Numbers are used to represent measures or count.

Example:
The length of a pencil is $15$ $15$ cm.
The number of pencils is $4$ $4$ .

Consider a class of $20$ $20$ students.

The heights of the students are measured. One of the student's height is $90 c m$ $90cm$

the height values of all students in a class is NOT uniformly $90$ $90$ cm. The heights usually vary and are NOT just one number.

The height values of eight students are given below in centimeters.

$90$ $90$ , $86$ $86$ , $99$ $99$ , $91$ $91$ , $87$ $87$ , $92$ $92$ , $90$ $90$ , $90$ $90$ .

The collection of information is called "data".

The word "data" means: collection of numbers given as measure or count of a quantity in different cases.

another form

On a plate, oranges, apples, bananas, and mangoes were available. A group of students take one fruit each as given in the order below.

orange
apple
mango
mango
apple
orange
banana
mango
mango
mango

This is another form of data. This is represented as number of student taking a particular fruit.

Is it easy to understand the data in this form? If the number of students is increased to $50$ $50$ , then the data, in this form, will not be easy to manage.

The same data is given as

$2$ $2$ students took oranges
$2$ $2$ students took apples
$5$ $5$ students took mangoes
$1$ $1$ student took banana

The representation given above is easier to read and understand.

With this example, The topic "Statistics" is introduced. Statistics is about collection, representation, and analyzing data.

data about state

The word "statistics", means collection, representation, and analyzing data.

In early days, "Statistics" was the data about a state (a country) and the word-form based of "state" is now used.

summary

Data : Collection of information is data.

Statistics : Study of recording, representing, and analyzing data.

Outline

The outline of material to learn "basics of statistics and probability" is as follows.

Note: Click here for detailed outline of "Basics of Statistics and Probability"

• Introduction

→ Introduction to Statistics

→ Organizing Data : Tally Table

→ Pictograph

→ Bargraph

• Data Analysis

→ Cumulative Frequency

→ Representative Values of Data

→ Central Tendencies

→ Bargraphs & Piecharts

• Probability Fundamentals

→ Predicting Future

→ Random Experiment

→ Probability

→ Standard Experiments

• Statistics Grouped Data

→ Grouped Data

→ Probability in Grouped Data

→ Class Parameters of Grouped Data

→ Methods to find Mean of Grouped data

→ Mode of Grouped data

→ Median of Grouped Data