How are statistical functions primarily used?

Statistical functions are primarily used for statistical analysis of data, which involves applying various mathematical methods to summarize, interpret, and draw conclusions from data sets. This is essential in numerous fields such as business, healthcare, social sciences, and engineering, where data-driven decisions are critical. Statistical analysis helps identify patterns, relationships, and trends within data, providing valuable insights that can inform decision-making processes.

While the other options highlight important aspects of working with data, they fall under specific applications rather than the broader purpose of statistical functions. Converting currency values pertains to financial calculations, defining normal distribution parameters relates to probability and statistics within a specific context, and visualizing data trends focuses on graphical representations of data rather than the underlying statistical analysis itself. Thus, the central role of statistical functions lies in analyzing data comprehensively, making option B the most accurate choice.