City leaders estimate that the current population of a city is 9.72 × 105 people. They predict that the population will increase by 1.1 × 104 people each year over the next decade. According to their prediction, which is the best estimate for the city's population in 4 years?

To find the estimated population of the city in 4 years, we need to calculate the population increase over 4 years and add it to the current population.

Population increase over 4 years = (1.1 × 10^4) × 4 = 4.4 × 10^4

Estimated population in 4 years = 9.72 × 10^5 + 4.4 × 10^4
Estimated population in 4 years = 9.72 × 10^5 + 4.4 × 10^4 = 9.764 × 10^5

Therefore, the best estimate for the city's population in 4 years is approximately 976,400 people.