To find the number of fish in the tank, we can use the formula:
\[ \text{Number of fish} = \text{Volume of tank} \times \text{Density of fish} \]
Given:
- Volume of the tank = 20 cubic feet
- Density = 0.2 fish per cubic foot
Substituting the values into the formula:
\[ \text{Number of fish} = 20 , \text{cubic feet} \times 0.2 , \text{fish/cubic foot} = 4 , \text{fish} \]
So, the number of fish in the tank is 4.