TABLE VII-5. Yield, income, and cost from nine locations
 in a farmer-managed maize and potato trial,
 Patzun, Guatemala.

 Yield Gross Total Net Net income/
Maize potato Income Cost Income Total cost


-metric ton/ha-


6.80
8.29
10.34
13.76
10.75
4.86
5.57
6.21
8.10


$/ha


2368
2710
2851
3740
3113
2092
1869
2298
2704


Improved
 1652
 1495
 1482
 1497
 1493
 1496
 1475
 1493
 1495


Traditional
 343
 359
 339
 341
 340
 350
 344
 353
 330


technology
 716
 1215
 1369
 2243
 1620
 596
 394
 805
 1209


Ratio



0.43
0.81
0.92
1.50
1.08
0.40
0.27
0.54
0.81


technology
379 1.10
628 1.75
312 0.92
334 0.98
326 0.96
475 1.36
391 1.14
537 1.52
166 0.50


Source: ICTA, Guatemala

standard error: Sx = (Sx2)l/2
 = 0.266

or with a calculator that is programmed to provide the
standard deviation, S

Standard error: Sx = S / (nl/2)
 = 0.7977 / 3
 = 0.266


4.66
4.74
3.08
3.81
4.00
5.47
3.44
4.98
4.93



3.86
5.28
3.48
3.61
3.56
4.41
3.93
4.76
2.65