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Linear Extrapolation Calculator

Linear Extrapolation Formula:

\[ y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1} \]

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1. What is Linear Extrapolation?

Linear extrapolation is a method of estimating values beyond the range of known data points by extending the straight line that connects two known points. It assumes the relationship between variables remains linear outside the observed range.

2. How Does the Calculator Work?

The calculator uses the linear extrapolation formula:

\[ y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1} \]

Where:

Explanation: The formula calculates the slope between two known points and extends this slope to estimate the y-value at the target x-coordinate.

3. Applications of Linear Extrapolation

Details: Linear extrapolation is used in forecasting, scientific research, engineering, and economics when making predictions beyond measured data points. It's particularly useful when data shows a consistent linear trend.

4. Using the Calculator

Tips: Enter two known (x,y) points and the target x value where you want to estimate y. Ensure x₁ and x₂ are different to avoid division by zero.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is linear extrapolation?
A: Accuracy depends on how well the linear assumption holds beyond the known data. The further you extrapolate, the less reliable the prediction becomes.

Q2: What's the difference between interpolation and extrapolation?
A: Interpolation estimates values between known points, while extrapolation estimates values outside the known range.

Q3: When should I not use linear extrapolation?
A: Avoid when data shows nonlinear patterns, when extrapolating far beyond known points, or when dealing with asymptotic behavior.

Q4: Can I extrapolate with more than two points?
A: This calculator uses two points, but methods like linear regression can incorporate more points for potentially better estimates.

Q5: What are alternatives to linear extrapolation?
A: Nonlinear methods like polynomial extrapolation, exponential smoothing, or more complex models may be appropriate depending on the data.

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