STEP-BY-STEP ANSWER:
Step 1: Gather a set of data points that include different levels of activity and their corresponding total costs.
Step 2: Define the independent variable (cost driver) and dependent variable (total cost).
Step 3: Use statistical software or calculation methods to fit a regression line, which minimizes the sum of squared differences between observed and predicted costs.
Step 4: Interpret the regression coefficients, where the intercept represents fixed cost and the slope represents the variable cost per unit.
Final Answer: Regression analysis provides a statistically robust method for estimating cost functions by linking cost behavior to measurable cost drivers.