To test the effectiveness of four different types of lawn fertilizer, each type was applied to six different lawns. The same size patch of lawn was mowed for all 24 test units and the grass clippings were weighed. Is there any indication that the fertilizers have an effect on the average weight of the grass clippings? Is there any reason to believe that the type of yard also affects the average weight of the grass clippings?
| |
Fertilizer 1 |
Fertilizer 2 |
Fertilizer 3 |
Fertilizer 4 |
| Lawn 1 |
10.3 |
11.7 |
8.2 |
9.8 |
| Lawn 2 |
8.6 |
12 |
8.9 |
9.2 |
| Lawn 3 |
8.2 |
9.3 |
10.7 |
9.6 |
| Lawn 4 |
10.6 |
10.5 |
9.3 |
10.1 |
| Lawn 5 |
9.1 |
9.8 |
10.4 |
9.5 |
| Lawn 6 |
8.2 |
12.4 |
9.6 |
9.0 |