The Nature of Probability The Nature of Probability y - PDF document

Elementary Statistics Elementary Statistics A Step by Step Approach Dr. Saeed Alghamdi Sixth Edition Room 542 by by Allan G. Allan G. Bluman Bluman Statistics Department http://www.mhhe.com/math/stat/blumanbrief http://www.mhhe.com/math/stat/blumanbrief SLIDES PREPARED SLIDES PREPARED Faculty of Sciences Faculty of Sciences BY BY BY BY LLOYD R. JAISINGH LLOYD R. JAISINGH King Abdulaziz University MOREHEAD STATE UNIVERSITY MOREHEAD STATE UNIVERSITY MOREHEAD KY MOREHEAD KY web sit Updated by Updated by Dr. Dr. Saeed Saeed Alghamdi Alghamdi www.kau.edu.sa/saalghamdy King Abdulaziz King Abdulaziz University University Chapter Chapter 1 1 Notes 1- -1 1 � …………………………………………………................ The Nature of Probability The Nature of Probability y � ……………………………………………………............ and and � ……………………………………………………............ Statistics Statistics � ……………………………………………………............ � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Objectives Notes 1-2 � Demonstrate knowledge of statistical terms. � …………………………………………………................ � Differentiate between the two branches of statistics. � ……………………………………………………............ � Identify types of data. � Identify the measurement level for each � ……………………………………………………............ variable. � Identify the four basic sampling techniques. � ……………………………………………………............ � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University 1

Objectives Notes 1-3 � Explain the difference between an � …………………………………………………................ observational and an experimental study. � Explain how statistics can be used and p � ……………………………………………………............ misused. � Explain the importance of computers and � ……………………………………………………............ calculators in statistics. � ……………………………………………………............ � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Introduction Notes 1-4 � Statistics is the science of conducting � …………………………………………………................ studies to collect, organize, summarize, analyze, and draw conclusions from data. � ……………………………………………………............ � Probability is the chance of an event P b bilit i th h f t occurring. � ……………………………………………………............ � Probability deals more with creating models deals more with creating models and theoretical data while and theoretical data while statistics statistics deals deals � ……………………………………………………............ more with applying models and real data. more with applying models and real data. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Introduction Notes 1-5 � A population consists of all subjects that are being studied. � …………………………………………………................ � A sample is a group of subjects selected from a population a population. � ……………………………………………………............ � Data are the values that variables can assume. � ……………………………………………………............ � Each value in the data set is called a data value or a datum . � ……………………………………………………............ � A data set is a collection of data values. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University 2

Introduction Notes 1-6 � In order to gain knowledge about events, � …………………………………………………................ statisticians collect information for variables that describe the events. � ……………………………………………………............ � A variable is a characteristic or attribute � ……………………………………………………............ that can assume different values. � Random variables have values that are � ……………………………………………………............ determined by chance. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Descriptive and Inferential Statistics Notes 1-7 � Descriptive statistics consists of the � …………………………………………………................ collection, organization, summarization, and presentation of data. � ……………………………………………………............ � Inferential statistics consists of generalizing I f ti l t ti ti i t f li i from samples to populations, performing � ……………………………………………………............ estimations hypothesis testing, determining relationships among variables, and making � ……………………………………………………............ predictions. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Variables and Types of Data Notes 1-8 � Qualitative variables can be placed into � …………………………………………………................ distinct categories according to some characteristic or attribute, e.g., flight classes, � ……………………………………………………............ departments, gender, …. � Quantitative or scale variables are numerical � ……………………………………………………............ in nature and can be ordered or ranked, e.g., � ……………………………………………………............ number of passengers, cargo weights, age, …. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University 3

Variables and Types of Data (cont’d.) Notes 1-9 Qualitative variables can be further classified � …………………………………………………................ into two groups. � Nominal —classifies data into categories that � ……………………………………………………............ can not be ordered or ranked, e.g., gender, b d d k d d departments, eye color, …. � ……………………………………………………............ � Ordinal —classifies data into categories that can be ranked, e.g., flight classes, ranking, � ……………………………………………………............ grade letters, …. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Notes Variables and Types of Data (cont’d.) 1-10 Quantitative or scale variables can be further � …………………………………………………................ classified into two groups. � Discrete variables assume values that can � ……………………………………………………............ b be counted, e.g., number of passengers, t d b f number of students in Stat 110, …. � ……………………………………………………............ � Continuous variables can assume all values between any two specific values, e.g., � ……………………………………………………............ heights, weights, …. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University Notes Variables and Types of Data (cont’d.) 1-11 Also, Quantitative or scale variables can be � …………………………………………………................ further classified into two groups. � Interval —ranks data, and precise differences � ……………………………………………………............ b t between units of measure do exist; however, it f d i t h there is no meaningful zero, e.g., IQ tests, � ……………………………………………………............ temperature, …. � Ratio —possesses all the characteristics of � ……………………………………………………............ interval measurement, and there exists a true zero, e.g., time, heights, weights, …. � ……………………………………………………............ Dr. Saeed Alghamdi, Statistics Department, Faculty of Sciences, King Abdulaziz University 4