1 / 11

1.2 - Displaying quantitative data with graphs

1.2 - Displaying quantitative data with graphs. (Histograms). Histograms. The most common graph of quantitative data. Classes: the intervals along the bottom axis. These need to be of equal width Frequency: the count of individuals of a class occurring

ashanti
Download Presentation

1.2 - Displaying quantitative data with graphs

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 1.2 - Displaying quantitative data with graphs • (Histograms)

  2. Histograms • The most common graph of quantitative data. • Classes: the intervals along the bottom axis. • These need to be of equal width • Frequency: the count of individuals of a class occurring • Relative frequency: the percent of the individuals in a class • (this is more useful, especially when you are comparing two sets of data with an unequal total of individuals)

  3. The following table presents the average points scored per game (PTSG) for the 30 NBA teams in the 2009-2010 regular season. Construct 2 histograms.One displaying the frequency and one displaying the relative frequency.

  4. Steps for constructing a histogram • 1st - divide the range of data into class of equal width. • 2nd - find the count and percent of individuals in each class. • 3rd - label and scale your axes • 4th - draw your histogram

  5. 1st step • What is the range of our data? • What would be a good class size to choose? • What are the classes?

  6. 2nd Step • Fill in a frequency table and a relative frequency table.

  7. Frequency Relative Frequency 3rd step PTSG PTSG

  8. Frequency Relative Frequency 4th step PTSG PTSG

  9. Don’t forget your “SOCS!” The data appears to be _______ with a peak of _____ . The histogram shows that the percent of points per games ranged from __________ The center of the data occurs around ______ Describe the data of the average points per game in the 2009-2010 NBA season. The _____ appear to be any outliers.

  10. www.whfreeman.com/tps4e How does class size effect the shape of the histogram?

  11. 2. Don’t use the counts or percents as the data. Use the data to find the counts and percents for your graph. 3. Use percents instead of counts when comparing distributions with different numbers of observations. Last Pieces of advice about histograms 4. Just because a graph looks nice, doesn’t mean it’s necessarily a meaningful display of data. (Excel is a terrible tool to use for statistical graphs) • 1. Don’t confuse histograms and bar graphs • Histograms are for quantitative data • Bar graphs are for categorical data

More Related