Announcements

Look here for late-breaking news affecting homework, midterms, or lectures.

Table of Contents:
HOMEWORK 7, QUESTION 3 CHANGED!!!!
Some Useful Tutorials
HW6: Don't do Number 4 and 8. Also Lab 3 will be due on Monday, 5/17, NOT Friday, 5/14.
HW5:  Don't do Number 4!  I've deleted it, so if you look now, there will be no Number 4.  If you already printed it out, however, you don't need to do it.  (We'll do it next week.)
HW 4
HW1
Trouble With ARC in Young Hall
Hints for HW3
QUIZZES and Their Solutions

Homework Number 7, Question 3, has some mistakes.  First, wherever you see "height" substitute "weight."  Second, whenever you see a phrase like
"probability average is x pounds heavier than y..." make it read "probability average is x pounds  OR MORE heavier than y..."  These changes have been put into the text of the homework assignment.
Some Useful Tutorials, which require a Java-enabled web browser. (Most are. Try it, and if it doesn't work, then you don't have Java enabled.)

Central Limit Thm:
    www.grad.cgs.edu/wise/
    www.stat.sc.edu/~west/javahtml/CLT.html
Quincunx
    http://stad.dsl.nl/~berrie1/index.html

HW4: Question 2 had a typo. It has since been corrected. The question asks you to compare
weight and TV viewing time, not weight and height as it previously said.

HW1:  Several sources of confusion abound.  Here are some answers to frequently asked questions.

1. How do I print the histogram?
    Well, this is awkward at best.  The only known way requires that you have a word processor that can handle graphics (like Word.)  Then you select and copy the histogram, and then paste into the word processor, and then print that page.  For the time being, if this is impossible, you can draw it by hand.

2. How do I start ARC in the Science Learning Center?
    Good question. Apparently, there were some programming difficulties, which will soon be fixed.  I asked the directory of the center, Carol Tierney about this, and she said:

Sorry it 's so complicated, but the shortcut should be fixed soon.
ENDQUOTE

3. What should I turn in?
    A hardcopy!  Handwritten is fine.  We don't have the facilities to manage email homework or homework on floppies.

Problems with ARC in Young Hall
There have been several difficulties with running Arc on the Young Hall computers.  These should all be resolved by next week.  The problem seems to be that the wrong software was installed.  But there is also some confusion about the name of the software:  its Arc. Not R-code.  (R-code, I believe, was an early, more primitive version of Arc, so the confusion is justifable, although R-code just won't work.)

Some other tips:

a) You should initiate Arc by, well, initiating Arc.  Some students are beginning by starting up xlispstat first, and then trying to load Arc.  It doesn't work this way.  Arc automatically starts xlispstat, but xlispstat doesn't start Arc.  Also, starting up R-code does nothing.

b) Avoid typing as much as possible, and instead  use the menus.  For example, you can type (histogram x) if you want to see a histogram of x.   But it is far better, and much more fun, to instead select "Graph & Fit", and make a histogram from that menu (under "Plot", choose only one variable and plot it on the H axis.)  This way you'll get to change the number of bins and play other games, too.

c) To upload data into Arc, first view the data from Netscape, and select "Save as..." and save it onto the Desktop.  Then, from Arc, choose "File: Load".  You will probably have to click on "view all files" if you are using a PC.  (And if you're in the Young Hall Lab, you are using a PC.)  This should initiate a dialog box that asks you to name each variable.  If you select the default name (which is Var0, Var1, etc.), you can type in your own name.

d) There is no way for you to save your work on the Young Hall computers, but if you bring a floppy, you can save it to the floppy.

I'm going to post this email on my homepage for the students to see.  I'll probably post it under "Announcements."

Sorry for the confusion!

Hints for HW 3
Some helpful ideas about using ARC just in time for HW 3.