1.1: Overview of Statistics Objective: To briefly go over an overview of Statistics CHS Statistics

Definition of Statistics  Statistics – a collection of methods for planning experiments, obtaining data, and then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on the data.  Let’s look at two different ways to interpret the definition:  Statistics (the discipline) is a way of reasoning, along with collection of tools and methods, designed to help us understand the world.  Statistics (plural) are particular calculations made from data.  Common misconceptions of statistics:  Data are values with a context. (Datum is the singular form of data). People often confuse these with statistics.  Think about it: Common advertisements such as, “Don’t drink and drive; you don’t want to be a statistic” are often incorrect. Can you find the mistake?

Population vs. Sample vs. Census  Population – the complete collection of all elements or subjects (scores, people, measurements, and so on) to be studied  Census – the collection of data from EVERY element in a population  Sample – a subcollection of elements drawn from a population  Examples: Population Sample Census

Important Key Points Throughout Chapter 1  Sample data must be collected in an appropriate way, such as through a process of random selection.  If sample data are not collected in an appropriate way, the data are useless.

Population vs. Sample - You Decide! In a recent survey, 1000 of the 7126 students of the Seneca Valley School District stated that they liked the idea of starting school after Labor Day. a)What is the population? b)What is the sample?