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An Overview of Statistics. Lesson 1.1. What is statistics?. Statistics is the science of collecting, organizing, analyzing, and interpreting data in order to make decisions. You are exposed to statistics almost every day!. Data.
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An Overview of Statistics Lesson 1.1
What is statistics? • Statistics is the science of collecting, organizing, analyzing, and interpreting data in order to make decisions. • You are exposed to statistics almost every day!
Data • Data consist of information from observations, counts, measurements, or responses. • The singular for data is datum.
Data Sets • A population is the collection of all outcomes, responses, measurements, or counts that are of interest. • A sample is a subset of a population.
Examples • A randomly selected group of 100 seniors at GCHS are surveyed about their future goals regarding further education. Identify the population and sample.
Parameter vs. Statistic • A parameter is a numerical description of a population characteristic. • A statistic is a numerical description of a sample characteristic.
Population Parameter or Sample Statistic? • In a recent study, 400 actuaries were surveyed. The average salary for a starting actuary was $45,000. • Sample statistic
Population Parameter or Sample Statistic? • 5.5% of the 2008 GCHS graduates have taken probability and statistics. • Population parameter
Study of Statistics • There are two branches of statistics we will be learning about this year: • Descriptive statistics is the branch of statistics that involves the organization, summarization and display of data. • Inferential statistics is the branch of statistics that involves using a sample to draw conclusions about a population. A basic tool in the study of inferential statistics is probability.
Descriptive of Inferential? • A survey conducted among 1017 men and women by Opinion Research Corporation International found that 76% of women and 60% of men had had a physical examination within the previous year. • Identify the descriptive aspect of this survey. • What inferences could be drawn from this survey?
Descriptive of Inferential? • Descriptive statistics invole the statement “76% of women and 60% of men had a physical examination…” • An inference drawn from the study is that a higher percentage of women had a physical examination within the previous year (talking about the entire population!)
Exercises • Pages 6-8 #1-4 all, 5-31 odd, 34-35 all.