Chapter One.doc

Chapter One Stats: branch of math that transforms #s into useful unfo for decision makers. Provides a way od understanding and redugin variation that is part of any decision-making process Provides a set of methods for analyzing the numbers. Help you find patterns in #s and determine differences in the #s are chance 4 applications: summarize bus. Data, draw conclusions from data, make reliable forecasts about bus activities, and improve bus processes Descriptive Statistics: collecting, summarizing, presenting, and analyzing a set of data (tables, charts, stats) Inferential statistics: used data that has been collected from a small group to draw conclusions about a larger group. Variables are characteristics of items or individuals and are what you analyze when you use a statistical method Sources of data fall into one of four categories ? 1) data distributed by an organization or an individual 2) a designed experiment 3) a survey 4) an observational study Categorical variables: have values that can only be placed into categories Numerical variables: have values that represent quantities Discrete variables: have numerical values that arise from a counting process Continuous variables: produce numerical responses that arise from a measuring process Nominal scale: classifies data into distinct categories in which no ranking is implied Ordinal Scale: classifies data into distinct categories in which ranking is implied Interval Scale: an ordered scale in which the diff btwn measurements is a meaningful quantity but does not involve a true zero point Ratio Scale: an ordered scale in which the diff btwn measurements involve a true zero point Statistical Package: A program engineered from the ground up to perform statistical analysis as accurately as possible Worksheets: tabular arrangements of data, rows and columns from cells Cells: boxes to make entries Workboxes: worksheets, info and results saved in one file