Introduction to statistics Statistics The word statistics which

Introduction to statistics Statistics: The word statistics which comes from a Latin word status, meaning political state. Or The words statistics refers numerical facts systematically arranged. In this sense the word statistics used like Statistics of price Statistics of road accident Statistics of crimes Statistics of birth Statistics of educational institutes Statistics is the set of numerical facts in the respective field. The word statistics means discipline that includes procedure and technique, used to collect and process and analyze the numerical data to make inference and reach to decision.

What is statistics Definition: Statistics are the numerical statement of facts capable of �analysis and �interpretation. The science of statistics is the study of the principles and the method applied in �Collecting �presenting, �analyzing and �interpreting the numerical data in any field of inquiry.

�Statistics is the science of collecting, organizing, presenting, analyzing, and interpreting numerical data to assist in making more effective decisions.

Types of statistics Descriptive statistics : are statistical procedures that summarize, organize and simplify data. if we ask from 8 students which have subject statistics, do you like statistics, the answer of 6 students is yes. This is called descriptive statistics. Inferential statistics: are techniques that allow us to study samples and then make generalizations about the populations from which they were selected. if we ask from 8 students which have one subject statistics, do you like statistics, the answer of 6 students is yes. This is called descriptive statistics and if we generalize the result that more students of this college like statistics is called inferential statistics on the base of this sample of six students.

Importance of statistics Statistics are an aid to supervision. Planning without statistics can not be imagined. Statistics are the eyes of administration. Statistics have made great improvement in agriculture and industry. e) Statistical data and statistical method have been found increasing useful in research in different fields. a) b) c) d)

Why a manager need to know about statistics 1) 2) 3) 4) Business managers in the 21 century have access to large amounts of information. A major issue is how to use the available information to make better decisions. Following are the four key reasons. To know how to properly present and describe information. To know how to draw conclusion about large population based only on information obtained from samples. To know how to improve process. To know how to obtained reliable forecast.

Population is the set of all individuals of interest in a particular study or A large mass of data or an aggregate of values or observation having some common observable characteristics is known as population. e. g if 600 students were admitted in kabul university science dept then the record of the 600 students constitute of population e. g. All people in the United States Parameter is a value which describes a population Sample: sample is a part or portion or subset of populations. Statistic is a value which describes a sample

A population is a collection of all possible individuals, objects, or measurements of interest. A sample is a portion, or part, of the population of interest

�Variable: A variable is a symbol, such is x, y, z which can assume any of a prescribed set of values. Ø The numbers of students in class, weekly wages, etc, are the examples of variable. A measurable quantity which vary from one value to another. �Types of variable. Ø Continuous variable: A variable which can assume any value between two given values. Example are weight of a boy, the monthly income etc. Ø Discreet or Discontinuous variable: A variable which cannot assume any values between two given values. Example numbers of accident in a months, number of children in a family, the number of students in a class.

Statistical data: Set of recorded information or observation is called data. Raw data: The recorded information in its original collected form is called raw data. Or When data are collected in original form, they are called raw data Data which can be described by discrete variable are called discrete data and those which can be described by Continuous variable are called Continuous data. Types of Data: Quantitative and qualitative Primary data: Primary data is the most original data and has not undergone through any statistical treatment. It is the data which is collected for the first time. Secondary data : The data which is gathered by someone else for his own or purpose before and you are going to use it Data which have gone through statistical treatment at least once.

Methods of collecting primary data 1 - Direct personal observation. The investigator collect the information directly from the source concerned. These information are highly accurate, reliable useful and are directly related to the purpose of inquiry. 2 -Indirect personal observation Some time the informants face hesitation or refuse to give direct correct answer or information. Than the information are gathered by questionnaire. 3 - Information through correspondence. In this method the investigator appoints trained agents or correspondents with the direction to collect required information using their own method and judgment and then communicate these information to the investigator or agency. 4 - Mailed questionnaire method. 5 - Registration.

Classification It is the process by which things are arranged in groups or classes. Tabulation: means a systematic arrangement of data in columns and rows that helps to a meaningful conclusion.

Statistical Notation �Scores or observations are represented by X and Y �N represents the number of observations, uppercase for populations and lowercase for samples � is used to stand for summations for example X is the sum of X

Statistics: The science of collecting, describing, and interpreting data. Two areas of statistics: Descriptive Statistics: collection, presentation, and description of sample data. Inferential Statistics: making decisions and drawing conclusions about populations

Population: A collection, or set, of individuals or objects or events whose properties are to be analyzed. Two kinds of populations: finite or infinite. Sample: A subset of the population. parameter: A numerical value summarizing all the data of an entire population. Statistic: A numerical value summarizing the sample data.

Classify the following as qualitative and quantitative data. 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) Nationality of the students in the university. Color of eyes of patients in a Hospital. Income of employees of Peshawar university. Heights of the students in college. Religion of people of Afghanistan. Weight measurement of students. Language of the peoples of the province. Income of Government servant. Colors of petal of 50 roses. The numbers of houses in a street.

State with the reason weather the following are discrete or continuous variables? 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) No’s of cars in the showroom Weight of boys Monthly expenditure of college students No’s of boys in the class room Height of a plant No of flowers in a garden No’s of cars passing through traffic signal between 7 AM to 9 AM Height measurement of boys in college No of rooms in a house Monthly salaries of college teacher in kabul university No of books in a library shelf No of liters of water in washing machine. Diameter of circle Temperature at place

1) 2) 3) 4) 5) The no of heads in four tosses of a coin The age of shopkeepers in Kabul city Time require to solve a question paper The speed of an aero plane The runs scored by bates man

Example: A college dean is interested in learning about the average of faculty. Identify the basic terms in this situation. The population is the age of all faculty members at the college. A sample is any subset of that population. For example, we might select 10 faculty members and determine their age. One data would be the age of a specific faculty member. The data would be the set of values in the sample. The parameter of interest is the “average” age of all faculty at the college. The statistic is the “average” age for all faculty in the sample.