Student instructions
Exponential modelling of the farm value of potatoes

In this activity, you will retrieve data on the farm value of potatoes from 1950 to 2005 from E-STAT, Statistics Canada's large database for students and teachers. Farm value of potatoes refers to the dollar value of the potatoes that are sold by farmers within Canada and internationally. You will import the farm value of potatoes data into a statistical software program to see if an exponential function model y = ca^x is a good fit for the farm value of potatoes data.

E-STAT instructions

1. Go the E-STAT website.
2. Select English.
3. Click on Search CANSIM on the left sidebar.
4. Type 001-0014 in the Search box and click on the Search button to retrieve Table 001-0014 – Area, production and farm value of potatoes, annual.
5. On the Subset selection page:
   1. Select Canada
   2. Select Total farm value of potatoes (dollars)
   3. Select 1950
   4. Select 2005
6. Click on the Retrieve as individual Time Series button.
7. On the Output specification page, under Screen output – table:, select Plain text: Table, time as rows.
8. Click on the Retrieve now button.

Generic statistical software instructions

Note: Specific instructions for dynamic statistical software (PDF, 51 Kb) (e.g., Fathom) are also provided.

1. Import your data into your statistical software program.
2. Save your file as Farm value of potatoes.
3. Create a new attribute, Years since 1950, using the following formula:
   Years since 1950 = Year - 1950
4. Create a scatter plot with Years since 1950 on the x-axis and Dollar value on the y-axis.
   Note: If you are using Fathom, indicate Dollar value 'thousands' for the y-axis.
   
   ***** Go to your worksheet and answer questions #1 to 5. *****
   
   
5. Plot the following function on your scatter plot:
   Dollar value = ca^{Years since 1950}
   Note: If you are using Fathom, indicate Dollar value 'thousands' = ca ^{Years since 1950}.
6. Alter the values of c and a until your function closely approximates the data in the scatter plot.
   
   ***** Go to your worksheet and answer questions #6 to 13. *****