Six Sigma Black Belt Certified Practice Exam 2025 – The All-in-One Guide to Master Your Certification!

A histogram is the optimal graphical representation for identifying the frequency distribution of data. It displays data by dividing it into intervals, or bins, along the x-axis, and the height of each bar represents the frequency of data points that fall within each interval. This makes it easy to visualize how often each range of values occurs, allowing one to see patterns such as central tendency, variability, and the shape of the data distribution (whether it is normal, skewed, etc.).

Other graphical representations serve different purposes. A pie chart is better suited for showing proportions within a whole, making it less effective for displaying frequency distribution. A box plot summarizes data by showing medians, quartiles, and potential outliers, but it does not convey how frequently different data values occur. A line graph tracks data points over time, which can show trends but does not provide a clear view of frequency distribution like a histogram does. Thus, histograms are specifically designed for analyzing the distribution of data, making them the most appropriate choice for this function.