Find the mean proportional (geometric mean) between 0.32 and 0.02.

Difficulty: Easy

Correct Answer: 0.08

Explanation:


Introduction / Context:
The mean proportional (geometric mean) m between two positive numbers a and b satisfies a : m = m : b, or m^2 = a * b. Hence m = sqrt(a * b). Compute accurately with decimals.



Given Data / Assumptions:

  • a = 0.32
  • b = 0.02
  • m^2 = a * b ⇒ m = sqrt(0.32 * 0.02)


Concept / Approach:
Multiply the two decimals and take the square root. Keep precision to avoid rounding errors that might push you toward a nearby option.



Step-by-Step Solution:
Product = 0.32 * 0.02 = 0.0064m = sqrt(0.0064) = 0.08



Verification / Alternative check:
Check proportion: 0.32 : 0.08 = 4 : 1 and 0.08 : 0.02 = 4 : 1; proportions match, confirming m.



Why Other Options Are Wrong:
0.34 and 0.30 are far too large; 0.16 would be m^2, not m; 0.06 does not satisfy the proportion check.



Common Pitfalls:
Confusing arithmetic mean with geometric mean; forgetting to take the square root after multiplying.



Final Answer:
0.08

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