The Agricultural Experiment Station of a university tested two different herbicides and their effects on crop yield. From 90 acres set aside for the experiment, the station used herbicide 1 on a random sample of 30 acres and herbicide 2 on a second random sample of 30 acres; they used the remaining 30 acres as a control. At the end of the growing season, the yields (in bushels per acre) were as follows:

Herbicide 1 81.2 81.1 79.9 84.6 80.4 74.4 81.7 90.1 102.4 89.2 92.0 91.7 75.9 95.1 76.1 83.0 88.0 80.5 73.6 80.4 103.2 85.9 73.6 80.0 82.4 79.5 99.8 96.6 81.3 94.7 Herbicide 2 94.8 90.9 85.2 83.3 95.5 85.4 87.1 89.6 83.7 88.7 91.4 85.4 89.0 92.4 85.0 91.0 89.2 100.9 88.5 90.3 87.6 80.7 90.0 101.0 92.1 97.9 92.5 88.8 89.4 100.1 Control 94.7 79.5 91.4 82.6 96.9 85.4 80.8 90.6 88.6 80.8 78.1 82.5 93.5 83.1 90.5 89.2 82.0 84.1 90.1 84.5 81.2 92.4 90.5 82.0 106.6 96.9 76.1 101.8 77.5 88.8