What is the precision for reporting the percentage finer than the 75 µm sieve when the result is less than 10%?

• A. Nearest 0.1%
• B. Nearest 1%
• C. Nearest 0.5%
• D. Nearest 2%

Answer: (A)

When the percent finer than the 75 µm sieve is very small, you want to show the smallest meaningful change in that value. Reporting to the nearest tenth of a percent (0.1%) provides enough resolution to accurately reflect tiny amounts of fines without implying precision beyond what the test can reliably provide. This finer rounding matches the accuracy of typical sieve and weighing measurements for low results, where rounding to a coarser step would hide small but real differences. In practice, once values exceed the low range, the rounding increments are often stepped up, but for results under 10%, the one-tenth-percent precision is the appropriate standard.