Power Regression Formula:
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Power regression is a type of non-linear regression that models the relationship between two variables where one variable is proportional to the power of another. It follows the form y = a × xb, where 'a' is the coefficient and 'b' is the exponent.
The calculator uses the power regression formula:
Where:
Explanation: The equation describes how y changes as x changes, with the rate of change determined by the exponent b.
Details: Power regression is commonly used in physics (e.g., gravitational force), biology (allometric scaling), economics (production functions), and many other fields where relationships follow power laws.
Tips: Enter the coefficient (a), independent variable (x), and exponent (b). The calculator will compute the dependent variable (y). All values can be positive or negative (except when x=0 with b≤0).
Q1: What's the difference between power and exponential regression?
A: In power regression, the exponent is applied to x (y = a×xb), while in exponential regression, the exponent is applied to the coefficient (y = a×bx).
Q2: Can x be negative in power regression?
A: Yes, but only if b is an integer. For non-integer exponents, x must be positive.
Q3: How do I find the coefficients for a set of data points?
A: You would need to perform logarithmic transformation and linear regression on the log-transformed data.
Q4: What does a negative exponent mean?
A: A negative exponent means y decreases as x increases (inverse relationship).
Q5: What are common examples of power laws?
A: Examples include Kepler's laws of planetary motion, the Pareto principle (80/20 rule), and metabolic scaling laws.