14. Statistical Techniques in Business & Economics (2)

2 ­ 1. f requency Distributions. Describing Data. Describing Data. Graphic PresentationsCopyright © 2003 by The McGraw­Hill Companies, Inc. All rights reserved. .Copyright © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ 2. When you have completed this chapter, you will be able to:. Organize raw data into frequency distribution Produce a histogram, a frequency polygon, and . a cumulative frequency polygon from . quantitative data Develop and interpret a stem­and­leaf displayCopyright © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ 3. Present qualitative data using such graphical . techniques such as a clustered bar chart, a. stacked bar chart, and a pie chart Detect graphic deceptions and use a graph . to present data with clarity, . precision, and . efficiency .Copyright © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ Frequency Distribution is a .grouping of data into . non­overlapping classes . (mutually exclusive) . showing the . number of observations . in each . category or . class all values in the . The range of categories includes all values. The range of categories includes in the . data set (collectively exhaustive classes) data set (collectively exhaustive classes)Copyright © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ Midpoint or Class Mark:. A point that divides a class . into two equal parts, . the of the upper and lower . class limits. . frequency:.The number of observations in each class. .Class interval:.The class interval is obtained by subtracting the lower limit of . a class from the lower limit of the next class, © 2004 by The McGraw­Hill Companies, Inc. All rights reserved. 2 ­ 7 Dr. Tillman is Dean of the School of Business. . He wishes to prepare a report showing the . number of hours per week students spend . studying. . He selects a random sample of 30 students and . determines the number of hours . each student studied last week. ., , , , , , , , , , . , , , , , , , , , ., , , , , 17.