A graphical representation where frequencies are plotted against class intervals is called

Correct option is C

Introduction
· In statistics, a frequency distribution is often represented visually to understand the shape, spread, and central tendency of a dataset.
· For continuous data, observations are grouped into "class intervals" (ranges of values) to make the data more manageable and interpretable.
· Graphical representations allow researchers to quickly identify patterns, such as whether the data is normally distributed, skewed, or contains outliers.

Information Booster

Histogram is the correct answer. A histogram consists of a set of adjacent rectangles where the base represents the class intervals (plotted on the X-axis) and the height represents the frequencies or frequency density (plotted on the Y-axis).

Unlike a bar chart, there are no gaps between the rectangles in a histogram because the class intervals represent a continuous range of data. This makes it the most effective tool for visualizing the distribution of quantitative variables.
· In a histogram, the area of each bar is proportional to the frequency of the corresponding class interval, which is crucial when class widths are unequal.
· It is used to identify the "modality" of the data, such as whether it is unimodal (one peak) or bimodal (two peaks).
· Histograms are essential for checking the assumption of "normality" before performing parametric statistical tests like t-tests or ANOVA.
· The midpoints of the tops of the bars in a histogram can be joined to form a "Frequency Polygon," another common statistical tool.
· According to standard biostatistics (referencing S. Chand texts), the histogram is the most widely used graphical method for frequency distribution of continuous variables.

Additional Information
· Stem and leaf plot is a hybrid between a table and a graph where data is split into a "stem" (leading digits) and a "leaf" (trailing digits); it shows individual data points rather than grouping them into formal class intervals.
· Pie chart is a circular statistical graphic divided into slices to illustrate numerical proportions; it is used for categorical (qualitative) data rather than continuous class intervals.
· Box plot, also known as a whisker plot, represents the distribution of data based on a five-number summary (Minimum, First Quartile, Median, Third Quartile, and Maximum) rather than plotting frequencies against intervals.