Use R to produce the back-to-back stem-and-leaf display in Figure 3.4—stored as Fig3-4.dat.

This is a tricky one, and it is more of a puzzle to work on. Can you get it to work? I suggest that you look at http://exploredata.wordpress.com/2012/08/28/back-to-back-stemplots/

Ignore his reference to LearnEDA—it no longer exists. Instead, use “install.packages(aplpack)” and then “library(aplpack).” The data file is available at www.uvm

\\.edu/~dhowell/fundamentals9/DataFiles/Fig3-4.dat. The data are tab separated, so use sep 5 “\t”

(The Web page on R for this chapter contains the necessary code for a different data set, but see if you can work it out for yourself. It’s fun when it finally works. The code using the dropbox feature is also there.)

Transcribed Image Text:

Figure 3.4 Total points in an actual course on psychological methods plotted sepa- rately for those who missed class often or attended regularly Missed Class Often Stem Attended Regularly 55 85 18 19 85 9732 0 6660 8441 74400 2222222222 20 21 23 24 1369 25 024456 26 123444577 27 012366788 28 012488 29 0112346678 8 30 31 0 32 018 Code |25| 6 = 256