Answer:
125 Dolphins
Explanation:
The number of dolphins varied linearly with the number of fish.
The number of dolphins = D
The number of fish = F
Hence:
D ∝ F
D = kF
When 400 fish were present 250 dolphins appeared
Solving for k
250 = 400k...... Equation 1
Also
when 300 fish were present, 200 dolphins appeared.
200 = 300k...... Equation 2
So: we find k = Constant of Proportionality
250 = 400k...... Equation 1
200 = 300k...... Equation 2
We Subtract Equation 2 from Equation 1
50 = 100k
k = 50/100
k = 1/2
How many dolphins would appear if 250 fish were present?
D = kF
D = 1/2 × 250
D = 125 Dolphins