Question

Which among the followings is the most appropriate statistical equivalent of the technique used in interpretation of soil texture from particle size data?

• A. Frequency distribution
• B. Mean
• C. Dispersion
• D. Percentile

Hint:

The particle size distribution (PSD) curve is mathematically a cumulative frequency distribution curve.
The x-axis represents the log of particle diameter (class interval) and the y-axis represents the cumulative percentage passing (cumulative frequency).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Soil texture refers to the relative proportions of sand, silt, and clay-sized particles in a soil mass.
The mechanical analysis of soil yields a particle size distribution (PSD) curve.
Detailed Explanation:
- A particle size distribution analysis measures the percentage (by weight) of soil particles falling within specific size limits (sand, silt, and clay).
- Statistically, this is represented by a ______frequency distribution______ (specifically, a cumulative frequency distribution), where the particle sizes are grouped into classes (intervals) and the cumulative percentage of particles smaller than a given size is plotted.
- The shape of this cumulative curve reflects the distribution of grain sizes.
- While specific percentiles (like $d_{10}$ or $d_{60}$) are extracted from the curve for engineering classification, the entire technique of dividing the continuous particle sizes into discrete sand, silt, and clay bins and plotting them is a representation of a frequency distribution.

Step 2: Final Answer:
The most appropriate statistical equivalent is the frequency distribution, corresponding to option (A).