Chapter 1 Introduction 1 Section 1.1 1.1 1) Statistics refers to numerical facts such as the age of a student or the income of a family. 2) Statistics refers to the field or discipline of study. Statistics is a group of methods used to collect, analyze, present, and interpret data and to make decisions. 1.2 Descriptive statistics consists of methods that help us organize, display, and describe data using tables, graphs, and summary measures. Inferential statistics consists of methods that use sample results to help make decisions or predictions about a population. 1.3 a. This is an example of inferential statistics because a poll was taken using a sample of adults and based on the results, conclusions are inferred with a certain margin of error. b. This is an example of descriptive statistics because information was gathered and tabulated, but no inference was made to a larger population. Section 1.2 1.4 An element is a specific subject or object about which the information is collected. A variable is a characteristic under study that assumes different values for different elements. An observation is the value of a variable for a single element. A data set is a collection of observations on one or more variables. 1.5 With reference to this table, we have the following definitions: • Member: Each cause of death included in the table • Variable: The number of deaths • Measurement: The number of deaths from each cause of death • Data set: Collection of the number of deaths from each cause of death listed in the table 1.6 a. Number of deaths b. Nine c. Nine (causes of death)