11. Explain the factors affecting the demand for water.

Using the census data given below, estimate the population of the city for the years 2070 AD, 2072 AD, and 2100 AD using the incremental increase method.

\begin{tabular}{|l|l|l|l|l|l|l|}
\hline Year (AD) & 2000 & 2010 & 2020 & 2030 & 2040 & 2050 \\
\hline \begin{tabular}{l}
Population \\
(nos)
\end{tabular} & 11000 & 30000 & 50000 & 90000 & 120000 & 135000 \\
\hline
\end{tabular}



Answer :

To estimate the population of a city for the years 2070, 2072, and 2100 AD using the incremental increase method, let's follow these steps:

### Step-by-Step Solution

Step 1: Identify the given census data

The census data includes the population counts for specific years:
- Year 2000: 11,000 people
- Year 2010: 30,000 people
- Year 2020: 50,000 people
- Year 2030: 90,000 people
- Year 2040: 120,000 people
- Year 2050: 135,000 people

Step 2: Calculate the incremental increases

To find the incremental increase in population between each decade:
- 2010 - 2000 = 30,000 - 11,000 = 19,000 people
- 2020 - 2010 = 50,000 - 30,000 = 20,000 people
- 2030 - 2020 = 90,000 - 50,000 = 40,000 people
- 2040 - 2030 = 120,000 - 90,000 = 30,000 people
- 2050 - 2040 = 135,000 - 120,000 = 15,000 people

So, the incremental increases are: 19,000, 20,000, 40,000, 30,000, and 15,000 people respectively.

Step 3: Calculate the average incremental increase

To find the average incremental increase:
Average Incremental Increase = (19,000 + 20,000 + 40,000 + 30,000 + 15,000) / 5 = 124,000 / 5 = 24,800 people per decade.

Step 4: Estimate the future populations

Based on the average incremental increase, estimate the populations for future years:

1. For the year 2070:
- Years to add = 2070 - 2050 = 20 years
- Population increase = (24,800 / 10) 20 = 49,600 people
- Estimated Population for 2070 = 135,000 + 49,600 = 184,600 people

2. For the year 2072:
- Years to add = 2072 - 2050 = 22 years
- Population increase = (24,800 / 10)
22 = 54,560 people
- Estimated Population for 2072 = 135,000 + 54,560 = 189,560 people

3. For the year 2100:
- Years to add = 2100 - 2050 = 50 years
- Population increase = (24,800 / 10) * 50 = 124,000 people
- Estimated Population for 2100 = 135,000 + 124,000 = 259,000 people

Thus, the estimated populations of the city for the specified future years are:
- For 2070: 184,600 people
- For 2072: 189,560 people
- For 2100: 259,000 people