What conclusion can Jeanette draw from her experiment with diabetic rats and the new drug?

The conclusion that Jeanette can draw from her experiment with diabetic rats and the new drug is that the drug was effective at lowering blood glucose. This conclusion stems from the results observed during her experimentation, where the treated rats exhibited a significant decrease in blood glucose levels compared to the baseline or prior measurements. A successful determination of effectiveness is generally supported by data showing that the treatment produced a measurable change in the health markers being observed, in this case, the blood glucose levels of the diabetic rats.

In a typical experimental setup, the treated group (in this case, the rats receiving the new drug) would be analyzed for changes compared to their untreated controls. If the treated group shows a statistically significant improvement in blood glucose levels, then it can logically be concluded that the drug has had a positive effect. Thus, the evidence supporting the drug's effectiveness is elucidated through the observed changes in the biological parameters measured during the experiment.