Introduction 1 Investigating with Data 2 2 Learning with Samples 5 3 Computers and Statistics 7 www apsu edu jonesmatt 1 1 Investigating with Data What Is Are Statistics Statistics is the art and science of learning from data This involves collecting analyzing interpreting and presenting data A statistic is a function of a data set Examples www apsu edu jonesmatt 2 Aspects of a Statistical Study A statistical study must be carefully designed in order to obtain meaningful data Descriptive statistics involves gathering organizing and summarizing data graphs charts tables averages standard deviations percentiles maximums etc Inferential statistics involves drawing conclusions about a population based on information from a sample www apsu edu jonesmatt 3 Examples 1 Esimate how much money you will make delivering pizzas next month 2 There were 26 confirmed cases of West Nile virus in Tennessee in 2003 3 The Dow Jones Industrial Average increased 1 73 from Thursday August 21 2008 to Friday afternoon August 22 2008 4 The 90th percentile of 455 exam scores is 83 5 In October 2002 ABCNews com reported 73 of Americans favor a law requiring all guns sold in the US be test fired first so law enforcement would have ballistic fingerprints in case a firearm is used in a crime www apsu edu jonesmatt 4 2 Learning with Samples In observational studies researchers simply observe and report attributes and measurements taken In designed experiments researchers adjust imposed factors then observe and report attributes and measurements taken Examples p 21 24 25 26 www apsu edu jonesmatt 5 Censuses are thorough but time consuming and expensive Sampling and experimenting are not as thorough but less time consuming and less expensive A simple random sample of n distinct individuals is chosen such that each set of n individuals is equally likely to be chosen this type of sampling is done without replacement Example 1 Al Bo Carmine Deb and Evgenia enroll in a class How can we randomly choose two students to form a committee www apsu edu jonesmatt 6 3 Computers and Statistics Pseudo random numbers are useful for taking samples for simulating phenomena Get them using Excel Minitab TI 83 84 calculator or other device We can use computers to 1 generate random numbers to obtain random samples 2 simulate random phenomena 3 run statistical analyses Examples www apsu edu jonesmatt 7
View Full Document
Unlocking...