Why is Statistics Important Foundational Concepts Consider This

Why is Statistics Important Foundational Concepts

Consider This • Marketing cheeseheads to residents of Ashland & Bayfield counties (in 1990) • Need to know the mean age and percentage of males Foundations I Slide #2

How Should You Proceed? • Want to know the mean & percentage male for the entire population – Is this possible or reasonable? • The best we can do is look at a sample (i. e. , a portion of the population) – How do we do that? • How are individuals selected? • How many individuals should be selected? Foundations I Slide #3

Complete the Class Exercise Foundations I Slide #4

Summary – Principles • We cannot “see” the entire population – i. e. , we must sample to learn • Variability is everywhere – among individuals – Natural Variability – among summaries of samples – Sampling Variability • Conclusions are uncertain – because population is unknown and variability Statistics helps with these issues That is WHY you are here!!! Foundations I Slide #5

Summary – Goals of Statistics • Description / Summarization – Distill large amounts of data into a few informative numerical or graphical summaries • Inference – Make conclusions about the entire population from information gathered from the individuals in a sample Foundations I Slide #6