To determine the population of Lead at any given year, we need to establish the rate of change in population over time. By comparing the population figures for 1940 and 2000, we can calculate the average annual decrease in population.
Population in 1940 = 7,520
Population in 2000 = 3,027
Number of years between 1940 and 2000 = 2000 - 1940 = 60 years
Average annual decrease in population = (Population in 1940 - Population in 2000) / Number of years
= (7,520 - 3,027) / 60
= 4,493 / 60
= 74.88
The average annual decrease in population is approximately 74.88.
To calculate the population of Lead for any given year (t) after 1940, we can use the formula:
Population = Population in 1940 - (Average annual decrease in population × t)
For example, to find the population in the year 1985 (45 years after 1940):
Population in 1985 = 7,520 - (74.88 × 45)
= 7,520 - 3,369.6
= 4,150.4
Therefore, the population of Lead in the year 1985 would be approximately 4,150.