To make a prediction using the regression equation \( y = 1,200(1.2)^x \), we will substitute \( x = 12 \) into the equation to find the projected population after 12 years.
Using the equation:
\[ y = 1,200(1.2)^{12} \]
First, we calculate \( (1.2)^{12} \):
\[ (1.2)^{12} \approx 8.9161 \]
Next, we multiply this value by 1,200:
\[ y \approx 1,200 \times 8.9161 \approx 10,699.32 \]
Since population counts are typically whole numbers, we can round this value to 10,699.
Therefore, the best prediction for the town's population after 12 years is:
D. 10,699