Stat 1000 Distance: Assignment 2 Tips (Distance/Online Sections)
Published: Sat, 01/19/13
My tips for Assignment 2 are coming below, but first a couple of announcements.
Please note that my first two-day review seminar for
Stat 1000 will be on Saturday, Feb. 2 and Sunday, Feb. 3, in room 100 St. Paul's College,
from 9 am to 6 pm each day. This seminar will cover the lessons in Volume 1 of my book. More info will be sent later about this seminar when everything is finalized. I am not taking registrations for the seminar as of yet.
Did you read my Tips on How to Do Well in this Course?
Make sure you do: Tips on How to Do Well in Stat 1000
Did you read my Tips on what kind of calculator you should get?
Did you miss my Tips for Assignment 1?
If you are taking the course by Classroom Lecture (Sections A01, A02, etc.), I will send tips for Assignment 2 once it is posted.
Tips for Assignment 2 (Distance/Online Sections D01, D02, D03, etc.)
Continue to study Lesson 1 in my study book (if you have
it) to learn the concepts involved in Assignment 2.
Don't have my book? You can download a free sample containing Lesson 1 at my website here:
Never use JMP to answer a question unless they specifically tell you to. Whenever
they do tell you to use JMP, never go out of your way to click red
triangles to add things to the graph (like put titles on histograms, or
label axes). Whatever JMP gives by default is all they require unless
they specifically request that you add something to the output or remove
something from it. Of course, I will always give you specific steps to
add/remove anything they do require.
When you are answering questions in Web Assign, always answer one box at a time. Type your answer in the box (or select the correct response) and then click "Submit Answer" immediately. DO NOT answer several questions before you submit any answers. If you submit one answer at a time, you will make sure you are correct before you proceed and also prevent any glitches where things get submitted accidentally.
Note also that any question that requires you to upload a file is not being marked at that time. You can go back and upload a new file as many times as you wish up to the due date. Don't be confused by the message telling you to read such and such in the book. That is them just warning you that no one has marked your submission and you may want to double-check you understood the question and ensure what you have uploaded is correct.
Ignore any references to Crunchit!.
You are using JMP 10 in this course. The assignment is just an old
assignment that they forgot to update. Use JMP 10 anytime they tell you
to use computer stuff.
When entering numbers into WebAssign, make sure you round off
as indicated. Round off, don't trim! For example, if your answer is
2.58 and you are told to round off to one decimal place, you would round
that to 2.6, don't just trim off the 8 and say the answer is 2.5. If
the next digit is a 5 or higher, you round up.
Make sure you have read your course info to help answer questions 1 and 2.
Question 3 should be done manually. Note, to enter the answers correct to 0.1, they mean round your answers off to one decimal place.
Question 4 should be done manually (i.e. using the Stat Mode in your calculator, not JMP). Be sure to read the Appendix at the back of my book to learn how to use
Stat Mode in your calculator to compute a mean and standard deviation
quickly. Note that you are told to keep two decimal places. Be sure to round off properly. Do not waste your time calculating the mean and standard deviation using the formulas (like my question 6 in Lesson 1). Let your calculator do it for you in moments.
Here is a link where you can download my appendix showing you how to use Stat Mode on several different calculators. Be sure to follow the steps I list for your make and model of calculator.
Question 5 (the IQ and GPA question):
Click the link to the data file, then select and copy
the entire data set (you can click "Ctrl A" on your keyboard to select
all, then click "Ctrl C" to copy it all). Having opened a "New Data
Table" in JMP, select "Edit" then "Paste with Column Names" to paste the
data in.
Double-click the "iq" column name at top (or highlight and right-click and select "Column Info") and confirm that JMP
has the "Data Type" as "Numeric" and the "Modeling Type" as
"Continuous", changing those settings in the drop-down list if
necessary. Click OK. Do the same for the "gpa" column.
Important:
Double-click the "gender" column (or highlight and right-click and select "Column Info") and make sure that JMP has the "Data
Type" as "Character" (it probably doesn't) and the "Modeling Type" as
"Nominal" (it probably doesn't), changing those settings in the
drop-down list if necessary. Click OK.
Finally, take a look at
the last row of data that has been pasted into JMP. If it just shows a
bunch of dots instead of numbers, click that row to highlight it then
right-click and select "delete rows" to delete that row. Of course, do
not delete any row that has numbers (data) in it!
To find the mean, standard deviation and median in part (a):
Select "Analyze" then "Distribution".
Highlight "iq" in the pop-up menu and click the "Y, Columns" button.
Click OK. You are then taken to a screen that shows a histogram among
other things. You will find the mean and standard deviation in the
"Summary Statistics" section and the median in the "Quantiles" section.
Type the correct values in the boxes provided in WebAssign
To make the boxplots and histogram in part (b): In the toolbar
at the top of your data spreadsheet, select "Analyze" then
"Distribution". Select the "gpa" column and click the "Y, Columns"
button. Click OK. Your histogram appears sideways but they didn't ask
you to switch it horizontally, so don't bother. If they want to see it
the typical way (and they will request that if they want it), click the
red triangle next to your variable above the histogram and select
Histogram Options from the drop-down menu. Select "Vertical".
They request the count on your histogram, so click the red
triangle next to "gpa" and select "Histogram Options" and select "Count
Axis".
Click the red triangle next to "gpa" and select "Quantile Boxplot" (if
it isn't checked already) and "Qutlier Boxplot" as well to get the
desired boxplots. Click the blue triangles next to "Quantiles" and
"Summary Statistics" to hide that stuff.
You will need to copy and paste this output into a document
to get ready to add the output from part (c) as well. Here is how to do
that:
Click the thin blue line near the top of the window that has
the histogram, etc. to reveal the toolbar. Select the icon that looks
like a fat white cross or plus sign "+". This is your "Selection"
tool. Your mouse cursor should now have changed from an arrow to that
white cross. Click the title bar that says "Distributions" at the top
of the output and that should select the entire output (histogram,
boxplots, etc.). Right-click and select Copy.
Now, open whatever program you use for word processing (such
as Word). In a new document, right-click and select Paste to paste your
output into the document.
They also ask you to comment on the graphs. I suggest you do
this by adding a note to the document you have just pasted the output
into. Just type your comments below all the JMP stuff. When they say
"comment on what feature of the data explains the difference between the
median and the median," they are implying they are different. What is
the shape of your distribution and what does that tell you should happen to the mean
compared to the median?
Leave this Word document open (but save it), as you will need to paste the stuff from part (c) into it as well.
To make the side-by-side boxplots in part (c):
Back in your data spreadsheet, select "Analyze" then "Fit Y By X".
Highlight "gpa" and click "Y, Response". Highlight "gender" and click
"X, Factor". Click OK. This should open a pop-up window with a bunch
of dots arranged vertically on a graph for Males "1" and Females "2".
If that does not happen, you probably did not follow my instructions
above to make sure the "gender" column is Character and Nominal. In
that case, close the window and make the appropriate adjustments in your
data table.
Now click the red triangle and select "Display
Options" (down near the bottom of the menu), then select "Box Plots" to get your side-by-side boxplots.
Click the thin blue line near the top of the window that has
the side-by-side boxplots, etc. to reveal the toolbar. Select the icon that looks
like a fat white cross or plus sign "+". This is your "Selection"
tool. Your mouse cursor should now have changed from an arrow to that
white cross. Click the title bar that says "Oneway Analysis of ..." at the top
of the output and that should select the entire output (graphs etc.). Right-click and select Copy.
Return to the document you already opened in part (b). Make
sure you are below the stuff you already have in the document. Perhaps
you should go to the end of what you have pasted and written for part
(b), and type CTRL-Enter (hold down the "CTRL" or control key while also
pressing the "Enter" key) to create a new page in the document.
Right-click and select Paste to paste the JMP stuff for part (c).
They also ask you to compare the boxplots. Again, just write
your comparison in your document below the JMP output you just pasted
in. Compare the shape, centre and spread of the two boxplots.
You are now ready to save and upload the file that answers part (b) and (c). In your Word document (or whatever program you are using), select "File" then "Save As" and select "PDF File". Type in whatever name you want the file to have in the "File name" section. Select which folder you want to save the
file in (I suggest you select "Desktop" so that the file will just
appear write on your desktop home screen. Click
"Save" or "Publish". You should now have your file ready to upload into the
assignment.
Question 6 should be done manually. Read my section in Lesson 1 on "The Effect of Changing Units on Centre
and Spread" to properly prepare for this question and look at my questions 17 and 18 for examples. Make sure you round to 2 decimal places as required.