1. The problem states that the population was 4 million in 1980 and increased by 0.041 million each year until 2007. 2. We need to find the population 10 years after 1980, which is in 1990. 3. The formula for population growth in this linear model is: $$P = P_0 + rt$$ where $P_0$ is the initial population, $r$ is the rate of increase per year, and $t$ is the number of years after 1980. 4. Here, $P_0 = 4$ million, $r = 0.041$ million/year, and $t = 10$ years. 5. Substitute the values: $$P = 4 + 0.041 \times 10$$ 6. Calculate the increase: $$0.041 \times 10 = 0.41$$ 7. Add to the initial population: $$P = 4 + 0.41 = 4.41$$ 8. Therefore, the estimated population 10 years after 1980 is 4.41 million.