The two graphs shown below represent data collected from the same lake
over a 20-year period. Over the course of the 20-year period, the oxygen
content of the water was measured, as well as the presence of E. coli found
in sewage waste. During the same time period, the population sizes of
varying fish species were also monitored.
Oxygen Content and Fish Population in a Lako
Carp
Oxygen
Sewage
Waste
Amount of
Specific Substances
Relative ananny
Trout
Walleye
1950 1955 1960 1965 1970
Whitefish
1950 1955 1960 1965 1970
Which of the following is the most likely relationship implied by the data
collected during the monitoring period?
O A. The whitefish population increases as oxygen levels decrease.
B. The carp population decreases as sewage levels increase.
O c. The trout population decreases as oxygen levels decrease.

We can see that the relationship between the number of trout and time passed is decreasing from the graph on the right because its line is decreasing. From the graph on the left, we can see that oxygen is decreasing as time goes on. Thus, we can interpret that the trout population decreases as oxygen levels also decrease; a proportional relationship.

The other options are incorrect because we can actually see that for...

A; the population of whitefish actually decreases as oxygen levels also decrease.

B; the population of carp actually increases significantly as sewage levels increase.

D; the walleye population actually also decreases overall as sewage levels increase.