What is regression analysis primarily used for?

Regression analysis is primarily used for estimating relationships among variables. This statistical method helps to understand how the dependent variable changes when one or more independent variables are altered. By establishing a mathematical model that represents these relationships, regression analysis can provide insights into trends, predictions, and causal relationships. For example, it can help businesses understand how changes in marketing spend may impact sales or how economic factors affect consumer behavior. This approach is fundamental for making informed decisions and strategizing based on data rather than assumptions.

The other options do not align with the primary purpose of regression analysis. While calculating probability distributions involves understanding the likelihood of certain outcomes, analyzing variance is focused on difference measurements between groups, and collecting samples pertains to data gathering methods. These are related fields within statistics but serve different objectives than regression analysis.