STAT 302 Statistical Methods Lecture 1 Dr Anirban Bhattacharya Assistant Professor Department of Statistics Texas A M University Outline 2 Preliminaries What is Statistics Course objectives Key definitions Course basics Instructor Dr Anirban Bhattacharya email anirbanb stat tamu edu Office 401D Blocker Building Office hours Monday 1 30 3 pm Wednesday 2 3 pm or by appointment These times are subject to change Announcements will be made accordingly Syllabus posted in Howdy and ecampus 3 Course basics TA Riddhi Ghosh email rghosh stat tamu edu Office TBA Office hours TBA 4 Prerequisites Math 141 147 or Math 166 or their equivalent is a prerequisite This course requires students to use elementary mathematics algebra and logical reasoning To do well in this course you must be able to apply logical thinking and critical analysis to statistical problems However if didn t have a quantitative course recently may need extra preparation 5 Help Session Help Session You can get help with your homework and course notes in 162 Blocker During the help session hours graduate statistics students at least 2 will be available to help you with your homework Hours Monday Thursday 10 am noon and 5 7 pm and Sunday 3 5 pm 6 Course materials All STAT 302 material will be disseminated via ecampus Log in to www ecampus tamu edu Alternatively log into Howdy you can find the ecampus tab on the top right corner I have opened the course for you so you should be able to view it Go to the content tab on the top left corner I shall create specific folders for lecture notes quizzes practice exams etc 7 Homework Posted on Thursdays and due the next Thursday at 11 59 pm unless mentioned otherwise Lowest grade will be dropped Submitted online through WebAssign Details will be given in class and also posted in ecampus Constitutes 15 of the total grade Prepare you for the exams 8 Quizzes Class participation 9 Regular quizzes in class on Thursdays Constitute 5 of the total grade final 10 15 minutes Work out 3 4 problems You can use your lecture notes during the quiz Exams 10 There will be two midterms one final exam Midterm I Tuesday March 3 In class Midterm II Tuesday April 14 In class Final Exam Tuesday May 12 1 3 pm in class Details posted in syllabus about excused absence if you miss an exam your responsibility to contact me asap Grade distribution 15 20 20 40 5 11 Homework Midterm 1 Midterm 2 Final exam Classroom quizzes A B C D F 90 00 100 80 00 89 99 70 00 79 99 60 00 69 99 0 59 99 Required materials The course notes posted periodically in ecampus will be selfcontained You can use The Practice of Statistics in the Life Sciences by Brigitte Baldi and David Moore ed 2 for supplemental reading though you are not required to buy this or any other book A calculator that has a square root function and can do calculations to at least 5 decimal places Advanced calculators are allowed but you may not use the advanced features in an exam 3 large grey scantrons to be used for the 3 major exams 12 How to do well in this class To do well in this course students must be able to apply logical thinking and critical analysis to statistical problems The homework problems and practice exam problems will help you practice these skills It is important to your success in this class that you put serious effort into your homework The practice exams are meant for testing concept and you shouldn t expect same type of questions in the exams 13 What is Statistics Statistics is a branch of mathematics dealing with the collection analysis interpretation and presentation of masses of numerical data Source http www merriam webster com dictionary statistics Statistics may be defined as a body of methods for making wise decisions in the face of uncertainty WA Wallis Statistics as a subject matter is a set of scientific principles and techniques that are useful in reaching conclusions about populations and processes when the available information is both limited and variable that is statistics is the science of learning from data 14 Importance of Statistics New York Times article from August 5 2009 For Today s Graduate Just One Word Statistics Statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write Samuel Wilks said this in his presidential address to the American Statistical Association in 1950 I keep saying the sexy job in the next ten years will be statisticians The ability to take data to be able to understand it to process it to extract value from it to visualize it to communicate it that s going to be a hugely important skill in the next decades Google s chief economist Hal Varian McKinsey Quarterly January 2009 Learning objectives Descriptive Statistics numerical and graphical summary of data Probability Mathematical foundation Inferential Statistics drawing conclusion about a population from data Data collection how to design a study 16 Language of Statistics Key Definitions Individuals Data sets contain information about one or more groups of individuals Individuals may also be called subjects or experimental units or observational units They may be people animals places or things Variables Information is organized into variables A variable is a characteristic of an individual A variable can take different values for different individuals Population Group of individuals about which inferences are to be made Sample A subset of the population of interest We gather information from the subjects in our sample to make inferences about the population Language of Statistics Key Definitions Simple random sample SRS of n subjects A sample in which every subset of n subjects of the population has an equal chance of being selected 18 Parameters and Statistics A parameter is a number that describes the population In practice the value of a parameter is not known because we cannot examine the entire population A statistic is a number that can be computed from the sample data without making use of any unknown parameters In practice we use a statistic to estimate an unknown parameter Sample statistics allows us to make inference concerning population parameters Examples 1 A researcher is interested in selecting the proper diet for shrimp or other sea animals because diet is an important aspect of sea farming The researcher wants to know What is the average weight of shrimp maintained on a specific diet for a period of 6 months The researcher has available to her an artificial pond full of shrimp The