Introduction to statistics - class-XII

A branch of mathematics dealing with the collection, analysis, interpretation, and presentation of masses of numerical data is called statistics.

Statistics are sets of mathematical equations that are used to analyze what is happening in the world around us.

Statistics helps in providing a better understanding and exact description of a phenomenon of nature.

Statistics helps in proper and efficient planning of a statistical inquiry in any field of study.

Statistics is the branch of mathematics that deals with the collection, organization, analysis, and interpretation of numerical data.

Statistics helps in presenting complex data in a suitable tabular, diagrammatic and graphic form for an easy and clear comprehension of the data.

Total wages paid by contractor to 18 laborers Rs 12 per day =$18\times 12=216 Rs

Bankers use statistical approaches to estimate the number of people who will be making deposits compared to the number of people requesting loans.

Statistics is the collection of methods used in planning an experiment and analyzing data in order to draw accurate conclusions.
So, the number of students in your class is an example of statistics.

Answer:- C) Statistical laws are exact.

Answer:- B) Statistics

Lottery method can be time consuming if a large population or sample is involved in this and also it becomes a very tedious and ambiguous task.

General census is official counting of a region's or nation's people and compilation of economics , social and other data usually for formulation of development policies and plans etc.

Use of table of random numbers is less time consuming and less expensive as compared to lottery as lottery deals with a large set of population or samples and also it is a time consuming method.

In a random number table, every digit has got an equal probability of being appearing and are independent of each other as selection of one number is not influenced by any other number.

Direct personal observation is the method adopted so that an intensive study of the population can be done. Direct observation helps in getting accurate results as their behaviour can be easily ascertained.

Under mailed questionnaire method, a well designed questionnaire is mailed to the informants
with a request to fill it up and return the same within the specific
time schedule. By this method, a wide range of people can be connected. The amount of non-responses is maximum in maid questionnaire method as most people are reluctant to answer the questions which are mailed.

By the $18^{th}$ century, the term statistics designated the systematic collection of demographic and economic data by states.

At the beginning of the $20^{th}$ century, William S Gosset has developed the methods for decision making based on small set of data.he has developed t-distribution theory.

The word statistics have been derived from Latin word "status".

The history of statistics can be said to start around in the year $1749$.

William Shakespeare used the word statist in his drama Hamlet $1602$.

Sample statistic will depend upon the sample chosen. 
It can be less than, greater than, equal to population parameter. 
It can assume the value of zero.
Ans-Option $E$.

Suppose that we had a data $A=\left{a _1,a _2.........a _n\right}$then

If it pertains to sample it is called a statistic, if it pertains to the population it is called a parameter.
Ans-Option $C$.

Given series is $9.1, 3.7, 5.6, 8.3, 11.5, 10.6$

(A) Statistics is liable to be misused is wrong 

Statistical data refers to quantitative information collected for analysis. Rainfall volume recorded over time is numerical data, whereas lists of names or cities are qualitative or categorical lists.

double graph is useful for comparison

Francis GP Neison introduced the first book of statistics in its title 'Contribution to Vital Statistics'.

Statistics was used by the British mainly for administrative and governmental bodies.

Numeral means numeric characters have to be involved. Numeric characters are numbers ranging from 0-1 and combinations between them.

Organised data is needed to draw meaningful inferences.

The word statistik used by German Gottfried Achenwall in the years $1749$.

The German stastistik, first introduced by Gottfried ache wall $(1749)$, originally designated the data analysis of state.

The word statistics and statistical are derived from the Latin word status, means political state.

Sir William Petty, a $17^{th}$-century economist used early statistical methods to analyse demographic data.

The Roman Empire was the first government to gather extensive data about population, area and wealth of territories that they controlled.

Karl Pearson is the founder of mathematical statistics.

Tomato is a not a data collection method, since tomato is a vegetable.
So, census, population and business strategy are types of methods of collection of data.

How many books does our class check out of the library each week? is a collection of data method. Because in the library they will use the statistics method of enter the books in order to check out.
But in option $A, C$ and $D$ are habitual question we will ask to your friends.

There are four important bases of classification:

(1) Qualitative Base (2) Quantitative Base (3) Geographical Base (4) Chronological or Temporal Base

(1) Qualitative Base:

When the data are classified according to some quality or attributes such as sex, religion, literacy, intelligence etc…

(2) Quantitative Base:

When the data are classified by quantitative characteristics like heights, weights, ages, income etc…

(3) Geographical Base:

When the data are classified by geographical regions or location, like states, provinces, cities, countries etc…

(4) Chronological or Temporal Base:

When the data are classified or arranged by their time of occurrence, such as years, months, weeks, days etc…

If the population figures are given for each State of India, then the data can be classified as quantitative data.

The data is of two types, primary and secondary data.

The first statement is true as we can easily track the ups and downs of datat form 1 year to the next.

In industries, statistics is applied majorly in areas of Quality Control.