Math Problem Statement

The population of a town in the decimal census is given below. Estimate the population for the year 1925. | Year | 1891 | 1901 | 1911 | 1921 | 1931 | |------|------|------|------|------|------| | Population (in thousands) | 46 | 66 | 81 | 93 | 101 |

Solution

To estimate the population for the year 1925, we will use linear interpolation, as it is a standard method for estimating values between two known data points.

Given data:

Year18911901191119211931
Population (in thousands)46668193101

We are tasked to estimate the population in 1925, which lies between 1921 and 1931.

Formula for Linear Interpolation:

P=P1+(P2P1)(t2t1)(tt1)P = P_1 + \frac{(P_2 - P_1)}{(t_2 - t_1)} \cdot (t - t_1) Where:

  • P1P_1 = Population at t1t_1 (starting year),
  • P2P_2 = Population at t2t_2 (ending year),
  • t1t_1, t2t_2 = Years of P1P_1 and P2P_2,
  • tt = Year to estimate the population for.

Substituting values:

  • P1=93P_1 = 93 (population in 1921),
  • P2=101P_2 = 101 (population in 1931),
  • t1=1921t_1 = 1921,
  • t2=1931t_2 = 1931,
  • t=1925t = 1925.

P=93+(10193)(19311921)(19251921)P = 93 + \frac{(101 - 93)}{(1931 - 1921)} \cdot (1925 - 1921)

Simplify step-by-step:

  1. Difference in population: 10193=8101 - 93 = 8,
  2. Difference in years: 19311921=101931 - 1921 = 10,
  3. Time interval: 19251921=41925 - 1921 = 4,
  4. Population growth per year: 810=0.8\frac{8}{10} = 0.8,
  5. Population increase from 1921 to 1925: 0.84=3.20.8 \cdot 4 = 3.2.

P=93+3.2=96.2P = 93 + 3.2 = 96.2

Final Answer:

The estimated population for the year 1925 is 96.2 thousand.


Would you like further details or an explanation?

Here are some related questions you can explore:

  1. What is linear interpolation, and how does it work?
  2. How do we estimate values beyond the given data range (extrapolation)?
  3. What are alternative methods to interpolation for population estimation?
  4. How can this data be visualized for better analysis?
  5. What is the rate of population growth between 1921 and 1931?

Tip: When using interpolation, always verify if the change is approximately linear, as this assumption underpins the accuracy of the method.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Interpolation
Population Estimation

Formulas

P = P1 + ((P2 - P1) / (t2 - t1)) * (t - t1)

Theorems

Linear Interpolation Method

Suitable Grade Level

Grades 8-10