EXPERIMENT A
Scientists believe that the amount of dissolved oxygen in a river affects the population sizes of freshwater
fish in the area. Scientists choose one stream and measure the amount of dissolved oxygen in the same
area of the stream. As the weather changes the dissolved oxygen in this area drops. Scientists also measure
the population size of salmon in the area. The scientists notice that as dissolved oxygen decreased, so does
the salmon population size.
Hypothesis:
Independent Variable:
Control Group:
Dependent Variable:
Experimental Group:
3 Constants: