| Finish
going through the Handout pages for In class, as above: 1,2,3,4,7
(nothing to hand in.) Then use the Handout Note the Index on the back
page to do the following. Hand in each problem as you complete it: All are due Monday, Day 10 (Feb.18). But try to get them done earlier! You don't need to complete them in order, but A is probably the one to start with. Also reading the output tables you make there is a skill needed for Exam 1. Use SPSS unless otherwise instructed. Print all graphs; copy down numbers onto the paper instead of printing those big tables. A. p. 33, 1.36 Rock sole. (This is file ex01-36.por; use filetype "All files" to find it.) To hand in: the SPSS stemplot, also a histogram, and find and write on your paper the mean, s.d. and 5-number summary. Also Describe as instructed in the book. B. p. 34, 1.38 Timeplot of rock sole. (the file is still the one from 1.36; files are not always under the problem number.) Which method should you use for your timeplot? Check and see that the years are in order and none are missing, so either method is OK. Get at least one graph, and if you're brave enough, try them both! Note: Your graph may not have labels on the axes, and it should! Sometimes SPSS doesn't label the graphs unless the Variable View, Label column has labels in it! If needed, Go back and label your variables, now do your graph again.. C. p.60, 2.36, breastfeeding and bones, comparing 2 groups. (Old saying: You lose a tooth with every child. Truth in it??) Note the form of the data file: all the change in mineral content values are in one column (bone) and a column (group) identifies each case with 1 for "other" and 2 for "breastfeeding" (check that's right by looking at the data in the book) Put in Labels, check that Measure is right. (Optional, add Value labels; like handout p. 2 bottom, to identify the 2 groups). I suggest side by side histograms, or parallel dotplots (handout p. 5) to start with. Who-Where-etc. Question about the data: Are these First-world women who are dutifully taking their calcium pills? No clue. D. Investigate the issue with data wrongly labeled Nominal or Ordinal. Use the file Studat for SPSS (Which you changed and saved after working p. 2) (SPSS for class BPS\ Studat Completer is what you should have gotten; use that one if you don't have yours. Some computers don't have it? Link above.. Studat complete doesn't have labels.) Make a dot plot and a histogram of Pulse. Now change the Measure for Pulse to Ordinal, in the Variable View in the Data Editor. Make a dot plot and a histogram of Pulse again. (The icon for Pulse should now not be a ruler. If it is, hit Reset, so the icon becomes the 3 towers. Then proceed.) Print the graph(s), compare to the first graph(s), and write on your paper what has happened, and what is wrong with the Ordinal graph(s). Hint: look at the "ruler scale" of the dotplot. The Histogram procedure just looks at the "Type" of the variable (Numeric/String) but the Dot procedure looks at the Measure! and treats Ordinal and Nominal data as if they are just Names, not numbers at all! No telling what a particular procedure will do!! Can this happen to you? Load the file for 1.37 study hours (You did this problem by hand.) What are the Measure values for these variables, and what should they be? E. Import a file: Go into the folder PC-BPSBigData (next to PC-SPSS folder) and open class.dat. (The Text Import wizard worked cleanly for me on this dataset.) From the README file: DATA: class.dat Data provided by students (n=270) in a freshman-level course. SEX 0=Male, 1=Female HAND 0=Right-handed, 1=Left-handed HGTH Height in inches STDY Time spent studying on a typical week night (minutes) Beware outliers! [is this the source of ex1-37?] COIN How much money in coins (not bills) are you carrying? INC Guess the income of a "typical American family" Check the Measure, put in appropriate labels. Make a histogram just of Height, and side-by-side or in-a-column histograms of Female and Male heights. Are the single-sex histograms roughly bell-shaped? Describe the shape of the mixed sex (total) histogram. The "Living Histogram" photo passed around in class with mixed sexes showed two clear equally high humps. Does the mixed-sex (total) histogram here show the same pattern? Why not ? |
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