To model the decreasing fox population, we start with the initial population of 640 foxes, which is decreasing by 3% per year. This means that each year, the population is 97% (or 0.97) of the previous year's population.
The exponential function representing the fox population, where \( x \) is the number of years from now, is given by:
\[ f(x) = 640(0.97)^x \]
Now, we need to estimate the fox population 10 years from now. We can do this by substituting \(x = 10\) into the function:
\[ f(10) = 640(0.97)^{10} \]
Calculating \( (0.97)^{10} \):
\[ (0.97)^{10} \approx 0.7374 \]
Now, substituting this value back into the population function:
\[ f(10) \approx 640 \times 0.7374 \approx 471.936 \]
Rounding this value, we can estimate that the fox population 10 years from now will be approximately 472.
Thus, the correct choice is:
B \( f(x) = 640(0.97)^x \) and the estimated fox population 10 years from now will be 472.