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Unformatted text preview: Sources of Data: 1) Existing sources like employee records, student records, medical history, … 2) Surveys- examples include teacher evaluations, amazon buyer surveys, … 3) Experiments- 4) Observational studies- Refer to Chapter 1 notes for information on types of sampling Sample Survey: the process of conducting a survey to collect data for a sample Good samples vs. Bad samples Below is info. From 113 that could be helpful Sample- is the part of the population from which we actually collect information and is used to draw conclusions about the whole. Census- is a sample survey that attempts to include the entire population in the sample. Experiment- deliberately imposes some treatment on individuals in order to observe their responses. The purpose of an experiment is to study whether the treatment causes a change in the response. The design of a statistical study is biased if it systematically favors certain outcomes. Selection of whichever individuals are easiest to reach is called convenience sampling . A voluntary response sample chooses itself by responding to a general appeal (write-in or call-in opinion polls) A parameter is a number that describes the population. A statistic is a number that describes the sample....
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- Spring '08
- percent frequency distribution, relative frequency distribution