A certain population of beavers builds dams across a stream to catch fish. Some years, the stream carries more water than in other years. The data below was collected by scientists studying the stream over the last four years.

Question

Year Stream Depth
(meters) Number of
Beaver Dams Number of
Beavers
1 1.20 6 17
2 0.92 4 12
3 1.45 7 21
4 0.78 2 9

If the depth of the stream next year is 0.52 meters, what will be the most likely result?
A.
The average size of a beaver dam will decrease.
B.
The size of the beaver population will increase.
C.
The average size of a beaver dam will increase.
D.
The size of the beaver population will decrease.

Answer 1

To analyze the data provided:

• The years with greater stream depths (Year 1 with 1.20 m, Year 3 with 1.45 m) have corresponded to a higher number of beaver dams and a larger beaver population.
• The years with lower stream depths (Year 2 with 0.92 m, Year 4 with 0.78 m) have shown fewer beaver dams and a smaller population.

Looking at the trend, as the stream depth decreases, the number of beaver dams and the beaver population also tends to decrease.

Since the depth of the stream in the upcoming year is 0.52 meters (which is lower than any of the previous years), it is likely that:

• The number of beaver dams will decrease due to less favorable conditions for dam building.
• The size of the beaver population will also decline since a decrease in available resources in the stream is generally not conducive to supporting a larger population.

Based on this analysis, the most likely result is:

D. The size of the beaver population will decrease.