Week Three LectureGraphic Display of Data and Descriptive StatisticsObjectivesUnderstand descriptive statisticsDevelop frequency distributions.Calculate measures of central tendency and dispersion.Utilize Microsoft® Excel®’s graphic and tabular techniques to represent descriptive statistical data.Descriptive statistics is a method of organizing, summarizing, and presenting data in an informative way. Two most important methods of data organization andpresentation are frequency distribution (tables) and visual display (charts). 1.Creating Frequency Distribution TableA frequency tableor frequency distributionis a table containing each category, value, or class of values that a variable might have and the number of times that each one occurs in the data.Rules for Creating Frequency Tables from Raw DataTwo questions must be answered to create the frequency table for continuous data.Question 1:How many classes should there be in the table?Question 2:How large (wide) should each class be?1.Decide on the size of class interval
2. Creating Charts from Raw DataThe graphical or visual descriptive tools, which generally include bar charts, pareto charts, pie charts and histograms enable us to summarize data. Examples of charts.
Guidelines for Creating Charts1.Select the right type of chart for the purpose you want to show.