• Download data for this lab.
• Extract the zip file.
• Copy all extracted files to your working folder properly named (e.g., E:\GEO242\Lab2).
• Open ArcMap 10, and click Blank map.
• Add shapefile to an empty map by connecting to the working folder.

• Open an attribute table of layer named ChiTract_SPC.
• Add a new field named PopChange: In ArcGIS 10, an Option button moved to the top. Click Options on the upper left corner of the open attribute table. Make sure you choose a right field data type among short integer, long integer, float, double, and string. Click here for an answer.
• Populate (fill in or calculate) the new field PopChange with population growth rate in fractional number: To do this, you have to right-click on the header of column PopChange, and click Field Calculator. Then type an appropriate expression in the input box.
• Now what? I am sure that you will get an error message. It happens because some records has zero value as a denominator (POP2000 in this case) in the expression you just entered. For example, census tract 581000 has 0 population in year 2000 as shown in the image.
• How many records (census tracts in this case) have zero population in year 2000? Click here for an answer and procedures.
• If you're done with query, click the Show Selected Records at the bottom of open attribute table. It turned out all of selected records have zero values for year 2000 and year 2004. It means that there were effectively no population growth in those selected census tracts.
• While these records (with zero population in year 2000) are selected, populate the new field with 0. You can do this using Field Calculator. If you're not sure what to do, click here.
• This time, you will select records where population in year 2000 is not 0. You can either use Query or simply switch selection. To switch selection, Options > Switch Selection. These selected records have non-zero population in year 2000.
• Now as you tried earlier, populate the new field with the number that represents a rate of population growth. If you're not sure what to do, click here.
• At this point, you should be able to have all records of a field PopChange filled.  
• Clear the selection: Options > Clear Selection

Now you are ready to make a map based on field values that are just calculated.

3. Make a choropleth map

• If you don't know how to make a choropleth (aka. graduated colors) map, click here.
• Play around Color Ramp in the Layer Property > Symbology window, such as diverging color scheme meaning you use two color hues (for instance green for population decrease, red for population increase). You stop whenever you think the color ramp is effective. 
• QUESTION: What census tract has the highest population growth from year 2000 to year 2004? What is the highest rate of population growth in percentage? To identify census tract, use the value of a field TRACT (six digit code). 
• Switch to the Layout View (View > Layout View), and insert all necessary map elements such as title, legend, north arrow, scale, as well as your name.
• Insert answers to the question in the format of "census tract code: rate of population growth in percentage" in the map. Make sure it's readable (not too small).
• Export the map into image file in jpg format (File > Export Map).
• For future reference, save this map in your working folder with a relative pathname. Click here for instructions on how to save map documents where the location of source data is stored using a relative path name.
• Make sure the image file looks properly (e.g., are answers readable?) before turn-in.  

You're done! Submit this map (jpg file) in Lab2 folder of D2L dropbox.