In a histogram, what does the x-axis typically represent?

• A. Score intervals
• B. Frequencies
• C. Relative frequencies
• D. Cumulative counts

Answer: (A)

In a histogram, the x-axis shows the numeric values of the variable divided into intervals (the bins) along the measurement scale, like 0–10, 10–20, etc. This tells you where data values fall across the range. The height of each bar represents how many observations fall into that interval (the frequency). Sometimes the same plot can display relative frequency or density on the y-axis, but the x-axis always represents the value ranges, not the counts themselves. A different plot, like a cumulative frequency curve, would be used to show cumulative counts.