Question

Viruses are infectious agents that often cause diseases in plants. Different viruses have different potency levels, and this fact can be used to detect whether a new virus is infecting plants in the field. In a potency comparison experiment, two viruses were placed on a tobacco leaf of 10 randomly selected tobacco plants in a field. The viruses were randomly assigned to one-half of each of the leaves. The table below presents the potency of the viruses, as measured by the number of lesions appearing on the leaf half.

Leaf # 1 2 3 4 5 6 7 8 9 10
Virus X 9 8 3 4 8 4 17 3 14 20
Virus Y 19 8 13 5 16 8 17 6 19 17

Test the hypothesis that there is no difference in mean number of lesions for Virus X and Virus Y

Answer 1

Well, since X has mean 9, and Y has mean 12.8, I'd say it looks bad for the hypothesis.

Answer 2

Hshsv