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Statistics is the science of gathering, describing, and analyzing data. Statistics is the numerical description of sample data. Definitions: Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

Data – information, in particular, information prepared for a study. Population – a particular group of interest. Parameter – a numerical description of a particular population characteristic. Census – when data is collected from every member of the population. Definitions: Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

Sample – a subset of the population from which data is collected. Sample Statistic – a numerical description of a particular sample characteristic. Definitions: Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

PopulationSample Whole groupPart of the group Group I want to know about Group I do know about Characteristics are called parameters Characteristics are called statistics Parameters are generally unknown Statistics are always known Parameter is fixedStatistics change with the sample Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

In a survey, 359 college students were asked if they had tried Vanilla Coke. 83 said yes. Population = all college students Sample = 359 college students A survey of 1125 households in the U.S. found that 65% subscribe to digital cable. Population = all U.S. households Sample = 1125 households Identify the population and the sample. Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists The average grade on Test 1 in Ms. Shirley’s statistics class is an 87. Parameter The average Math score for all high school graduates on the SAT was a 519. Parameter In a survey of 135 college students, 52% of them said they plan to attend graduate school. Statistic Is the numerical value a parameter or a statistic?

Identify the population and sample. Population = all families of the students at the school Sample = 195 families Does the value “76%” represent a parameter or a statistic? Statistic The principal of a large K-12 school is considering adopting a dress code for the upcoming school year. Before going to the school board, he wants to know the percentage of parents who would favor a dress code. He randomly chooses 15 families from each grade to interview. Out of the 195 families surveyed, 76% favor a dress code. Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

Descriptive statistics – gathers, sorts, summarizes and displays the data; “just the facts”. Inferential statistics – uses descriptive statistics to estimate population parameters; an educated guess about the population based on the facts. Branches of Statistics: Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists

Introduction to Statistics 1.1 Getting Started HAWKES LEARNING SYSTEMS math courseware specialists In a survey of 100 students, 83.2% of students are happy with the food in the cafeteria. Identify the descriptive statistic(s). What inferences can be made? Descriptive statistic: 83.2% of the 100 students surveyed are happy with the food in the cafeteria. Possible inferences: 83.2% of all students are happy with the food in the cafeteria.