A study sought to demonstrate that soy beans inoculated with nitrogen-fixing bacteria yield more and grow adequately without the use of expensive environmentally deleterious synthesized fertilizers. The trail was conducted under controlled conditions with uniform amount of soil. The initial hypothesis was that inoculated plants would outperform their uninoculated counterparts. This assumption is based on the fact that plants need nitrogen to manufacture vital proteins and amino acids, and the nitrogen-fixing bacteria would make more of this substance available to plants, increasing their size and yield. There were 8 inoculated plants (I) and 8 uninoculated plants (U). The plant yield measured by pod weight (gm) for each plant. We analyze the data using SAS's TTEST procedure and observe the results shown in Table 1 (see page 6). Based on those findings, answer the following questions.
1) Report and interpret the 95% confidence interval of the mean of the pod weight (gm) in the inoculated plants (I) group.
2) Identify the dependent variable and the independent or explanatory variable(s) in this study. Also, state the non-directional Null and Alternative hypotheses.