Answer
2012
Work Step by Step
We set the given equation for whole milk equal to 45 pounds per year to find:
$$ 45 = -2.11t+69.2$$
Then, follow PEMDAS. In other words, first address parentheses, and then resolve exponents. Next, simplify division and multiplication, and lastly address subtraction and addition. This gives the answer:
12
We know that 12 corresponds to the year 2012, so this will be our final answer.