Section 2.2b Graphical Displays of Distributions

Fully describe the distribution of this data.

 D8 – What information is lost when you use a relative frequency histogram.  P6 Refer to page 5 Display 1.1  Which variables are quantitative and which are categorical  P8 Make histograms of data for average longevity and then max longevity from display Describe differences in shape, center, spread. Why do these occur.

 P8 Convert the frequency histograms into relative frequency histograms.  P10 Using Rel Freq Hist from 2.28 on p. 47.  Estimate the proportion of mammals with a life expectancy of less than 50 years.  Describe the shape of the distribution  Estimate the median of this distribution

 Shows distribution much like Dot Plots and Histograms, but uses a different method.

 You can also use to compare two data sets back to back.

 Use with relatively small amount of data  You want to see individual values  You want to find mean, median or mode  You want to compare 2 groups (back to back)

 Use with categorical data  The horizontal axis is where you list the categories.  The bars are then used just like a histogram  There is typically a separation between the bars.

 1 GroupComparison of 2 Groups

 Stats  Page 53 E15, 20, 21, 22, 23, 25  AP  Page 53 E15, 23, 24, 25  Read Section 2.3