Answer:

The correct answer is D. Histogram

Explanation:

A histogram is the most appropriate diagram for estimating the mode of a grouped frequency distribution. Here’s why:

1. A histogram displays the frequency distribution of continuous data in adjacent rectangular bars.
2. The height of each bar represents the frequency or relative frequency of data in that class interval.
3. The mode in a histogram can be visually estimated as the highest point of the distribution, or the midpoint of the class interval with the highest frequency.
4. For grouped data, the histogram provides a clear visual representation of where the data is most concentrated, which corresponds to the mode.
5. Other diagrams mentioned in the options are less suitable:
   • Component bar charts are used for comparing parts of a whole across categories
   • Pie charts show the proportion of different categories in a whole
   • Z-charts (or run charts) are used to show data over time
   • Ogives (cumulative frequency curves) are used to find median and percentiles, not mode

Therefore, among the given options, a histogram is the most useful diagram for estimating the mode of a grouped frequency distribution.