When utilizing linear regression, what assumption is often made about the relationship between variables?

When utilizing linear regression, the primary assumption is that there is a linear relationship between the independent variable(s) and the dependent variable. This means that changes in the independent variable(s) are expected to produce proportional changes in the dependent variable. This linearity assumption is essential for the validity of the results obtained from linear regression analysis, as the method seeks to model the relationship by fitting a straight line through the data points.

By assuming a linear relationship, linear regression aims to minimize the differences between the observed values and the values predicted by the model, typically using the least squares method. If the actual relationship between the variables is not linear, the regression model may not accurately represent the data, leading to potential misinterpretation and poor predictive performance.