A microbial ecologist is interested in whether the microbial community of a pond changes when it rains. She knows that rainfall will increase the number of bacteria, but she is interested in the pattern of diversity. She collects a water sample from a pond two days before a rainfall and two days after and plates her samples on agar (a method to measure bacteria) and counts the number of colonies she observes for each of three bacteria: E. Coli, Salmonella, and Giardia. In the pre-rain sample she observes 21, 57, and 32 colonies respectively. In the post-rain sample she observes 59, 83, and 88 colonies respectively.
To determine whether there appears to be a statistically significant relationship between rainfall and bacterial diversity she would conduct a \chi 2 analysis. When performing this analysis, which of the values below is closest to the contribution to the \chi 2 statistic from the "pre-rainfall : Salmonella" category?
A microbial ecologist is interested in whether the microbial community of a pond changes when it rains. She knows that rainfall will increase the number of bacteria, but she is interested in the pattern of diversity. She collects a water sample from a pond two days before a rainfall and two days after and plates her samples on agar (a method to measure bacteria) and counts the number of colonies she observes for each of three bacteria: E. Coli, Salmonella, and Giardia. In the pre-rain sample she observes 21, 57, and 32 colonies respectively. In the post-rain sample she observes 59, 83, and 88 colonies respectively.
To determine whether there appears to be a statistically significant relationship between rainfall and bacterial diversity she would conduct a \chi 2 analysis. When performing this analysis, which of the values below is closest to the contribution to the \chi 2 statistic from the "pre-rainfall : Salmonella" category?
2.02
4.04
3.03
1.01