Graphs good and bad
Download
1 / 19

chapter10 - PowerPoint PPT Presentation


  • 263 Views
  • Updated On :

Graphs, Good and Bad MA155 Chapter 10 Organizing Data The first step in data analysis is to display the data in a graph. Look first for the overall pattern in the data, and then for striking exceptions to that pattern.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'chapter10' - jana


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Graphs good and bad l.jpg

Graphs, Good and Bad

MA155

Chapter 10


Organizing data l.jpg
Organizing Data

  • The first step in data analysis is to display the data in a graph.

  • Look first for the overall pattern in the data, and then for striking exceptions to that pattern.

  • After looking at the graphs, you can use well-chosen numerical descriptions.


Describing distributions l.jpg
Describing Distributions

  • Distributions

  • The distribution of a variable tells us what value the variable takes and how often each value occurs.


Data tables l.jpg
Data Tables

  • Clearly Labeled

  • Units are stated

  • Source of Data



Pie charts l.jpg
Pie Charts

  • A whole is divided into parts

  • Steps

    • Draw a circle

    • Make wedges that are representative of the proportion

  • The parts do make a whole



Bar graph l.jpg
Bar Graph

  • The height of each bar shows the proportion

  • It clearly shows the results

  • They are easy to make



Types of variables l.jpg

Categorical Variable

Places an individual into one of several groups or categories

Quantitative Variable

Takes numerical values for which arithmetic operations make sense

Types of Variables


Categorical examples l.jpg
Categorical Examples

  • Race

  • Sex

  • Employment Status

  • Hair Color

  • Type of Car


Quantitative examples l.jpg
Quantitative Examples

  • Measurements made on scales of equal units

  • Examples

    • Height in inches

    • Reaction time in seconds

    • Temperature in degrees Celsius


Remember l.jpg
Remember

  • Not all numbers carry the same information

  • Luke is a skateboarder.

  • Luke finished first at the 2000 Gravity Games

  • Luke scored a 92.60 on the street course.

  • The scale of measurement depends on the measuring process, not on the property measured.


Displaying distributions l.jpg
Displaying Distributions

  • To display the distribution of a variable measured in a nominal scale, use a pie chart or a bar graph

  • Pie charts emphasize how individual counts or percents are related to the whole

  • Bar graphs emphasize how quantities compare with one another.

  • Use pie charts and bar graphs when displaying the distribution of categorical variables.


Pictograms l.jpg
Pictograms

Source: http://www.usatoday.com


Line graphs l.jpg
Line Graphs

  • Show the behavior of a variable over time

  • Horizontal Axis Time

  • Vertical Axis Scale of Variable


Scales l.jpg
Scales

  • The scales of a line graph can cause a graph to be misleading


Making good graphs l.jpg
Making Good Graphs

  • Must be clearly labeled

  • Units stated

  • Source of Data

  • Make the data stand out!


Homework l.jpg
Homework

  • Read Chapter 11

  • Suggested Problems:

  • 10.1, 10.3, 10.9, 10.13, 10.17, 10.27