AEB 6933
 Spring 1995
 Exercise FA2


 1. Load the data from the table in Exercise No. 1 in a spreadsheet.
 Use the same orientation as in the table, i.e., farms are the rows and
 treatments are the columns. You can calculate the averages as a means
 of verifying accuracy of the data entered. This data set will be the
 basis for a number of analyses we will be doing. Be sure to save it
 in this form.

 2. Now we will set up the data to facilitate estimation of the
 production functions from Exercise No. 1 on the computer using the
 data from all eight farms. By copying and moving your data, set up
 another working table as below in order to calculate the response to
 P205.

A A. P205 (P205)2 N = 0 N = 50 etc.
 0 0 400 1240
 2- 0 0 1530

 I 25 625 790
 2- 25 625 1670
 50 2500 1670
 50 2500 1410

 50 2500 1370 3510

 You should aye 24 rows of data be careful not to include the
 averages! Y -- -A

 3. Using symbols in an x-y graph format, look at the data for N = 0
 (compare yield only with the levels of P205, not the squared values).
 Discuss.

 4. You can now estimate the equation by regression using (on Quattro-
 Pro) the commands T-A-R, with the two columns for P205 and (P205)2 as
 the independent variables and the column for yield as the dependent
 variable. The equation should be the same as the first you estimated
 in Exercise No. 1 by the visiographic method.

 5. Repeat for the other three levels of N. Are all the equations the
 same as you got from the visiographic method? They should be.

 6. ihowthe -our equations on a single graph. Can you figure out how
 to do this and get a smooth curve, not just two straight lines going
 through three points?


7. Interpret the results.