Evaluate Claims of Human Impact Practice Test

Students are evaluating claims about human impact on a river after a factory installed a filter system in 2022. They have one shared set of observations from the same sampling site.

Claims (some may be unsupported or overstated):

• Claim 1: The filter system reduced the amount of dissolved copper in the river.
• Claim 2: The filter system made the river water safe for all uses.
• Claim 3: Because copper went down, the filter system must have reduced all types of pollution.

Evidence (dissolved copper, $bc$g/L):

• 2021: 19
• 2022: 11
• 2023: 10

Which claim is not supported by the evidence?

A farm began using a new irrigation method in 2021 to reduce water use. Students measured the farm’s total water used each growing season and the crop yield.

Claims (some may be unsupported or overstated):

• Claim 1: The new irrigation method reduced total water use.
• Claim 2: The new irrigation method increased crop yield.
• Claim 3: Because water use went down, the new method is the only reason yield changed.

Evidence:

• Water used (million liters): 2020 = 52, 2021 = 41, 2022 = 40
• Yield (tons): 2020 = 18, 2021 = 17, 2022 = 19

Which statement matches the data without adding extra cause-and-effect claims?