Graphics in Excel Assignment.

You should produce a time series graph plotting ONE of the trends on the Bureau of Justice Statistics site (other than Property Crimes, which I have used as an example).
If you can't get through to the BJS site, use one of the other Data Sources for Sociology and Criminal Justice Students.

Just double click twice on one of the graphs to get the numerical data.  Enter the years and the data for ONE variable into Excel.    Compute the regression equation, and use it to plot the predicted values for each year on a second graph.  Prepare a graph showing both the observed and the predicted values.  Also use the regression equation to predict the rate for the year 2000.

For an example of this assignment, check the Property Crimes Excel file http://crab.rutgers.edu/~goertzel/propertycrime.xls

If you wish to submit this to WEBCT, you should submit the EXCEL file in *.xls format.

Here are some pointers on using Excel, based on problems that have come up in class:

1.  The "Data Analysis Tool Pak" must be installed on the computer you are using.  If you have Excel at home or at work, it may not have been installed.  You have to install it from the CD-ROM using the tools/add-ins command.  If you can't find it on the computers at Rutgers, first check the hint in item 2, then see if you can install it.  If that doesn't work, get help from computer center staff.

2.  If you still can't find the "Data Analysis" line on the "Tools" menu, it may be because you have the cursor on one of the graphs you have created.  The cursor has to be on the spreadsheet for the Data Analysis line to come up.

3.  When using the "regression" data analysis box:  first put the cursor in the y box, then highlight the cells for the dependent variable, then move the curson to the x box, and only then highlight the x data (the years), then move to the box for "output range" and then highlight the cell you wish the output to begin in.  It doesn't work if you highlight the data first, then click on the box you wish to use.

4.  When entering a formula to do your projections, make sure you click on the "=" sign before the box that shows the contents of the cell.  A formula must begin with an "=".

5.  When you do the regression make sure "constant is zero" box  has not been checked.

6.  If the spreadsheet has numbers instead of letters for the column labels, go to tools/options/ general and disable the "R1C1 reference style."

Here are some pointers if you need help in preparing the regression equation:

The best thing is to open the sample file I posted at:   http://crab.rutgers.edu/~goertzel/propertycrime.xls
and use it as a model.

Put the cursor on cell C3 where you see the number 563.3
Then look in the box just above, to the right of the =, which shows what is really in the box.  You will see the formula:

=-13.3815* A3 + 26977.99

A formula has to begin with an = sign, which tells Excel it is a formula.

In this example the "*" means "multiply" and the "+" means add,

  -13.3815 is the regression coefficient, which you find in cell B57

                          A3 is the address of the cell where the first date is, in this example 1973

                           26977.99 is the Intercept, also found under the word "Coefficients" in cell B56

Your assignment should end up very much like this example, only the numbers will be different.