# Linear Equation Unknown Variable Calculator, Formula & Example Calculation

## Linear Interpolation Calculator

Linear interpolation calculator - step by step calculation, formula & solved example to find the linear equation unknown variable in the XY coordinate system or plane. It's an online geometry tool find the missing linear interpolation value lies between to known variables or rates. The line coordinates (x1, y1), (x2, y2) & (x3, y3) in the XY plane are used in this calculator to find out the point slope form of a line unknown value of a linear equation, which lies between the two known variables.

### Linear interpolation

It's a method of curve fitting using linear equation, calculates the linear equation unknown variable as if it lies between two known polynomials or variables on a straight line. Linear Interpolation is a simplest way to find out the unknown or missing variable in a linear equation. Such calculations are deeply employed numerous applications including computer graphics and particularly numerical analysis in mathematics. It is a simple form of interpolation.

### Formula

Linear interpolation to find the unknown variable on a XY coordinate system or plane mathematically represented by the below formula

### Solved Example

This below solved example let users to understand how the example values are being used in this calculation to find the unknown variable of a linear equation.

Problem:
Find the unknown variable y2 where the values of x1 = 5, x2 = 7, x3 = 9, y1 = 12 & y3 = 15.

Solution:
Given
1 = 5, x2 = 7, x3 = 9,
y1 = 12 & y3 = 15
y2 = ?

Apply the values in the y2 equation
y2 = ((x2 - x1)(y3 - y1) / (x3 - x1)) + y1
= ((7 - 5) * (15 - 12)/(9 - 5)) + 12
= ((2 * 3)/4) + 12
y2 = 13.5

This step by step calculation, formula & solved example to find the unknown variable of a linear equation on XY plane may help users to understand, practice and perform linear interpolation calculations. When it comes to online for quick calculations, this linear interpolation calculator may help the user to perform & verify the results of such calculations.

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