20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
Explanation:
D. average hamster weight decreases with an increase in the daily amount of a drug until the hamsters reach a minimum possible weight.
Trend: There was a gradual decrease in the hamster's weight til a minimum was reached, after with the rate of its change in weight with treatment over time plateaued.
Trends are gradual notable changes or patterns over a series of data points on a line or curve of a graph. These allow for summarizing data and predicting results. A data summary provides a comprehensive report of experimental findings. This makes the analysis of data easier by answering key research objectives outlined in the experimental procedure. Summaries allow for tracking trends and procedural changes, observations and potential; this makes it easier to arrive at conclusions faster.
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