Evaluate: √(3.6% of 40). Choose the exact numerical value.
Correct Answer: 1.2
Introduction / Context:This evaluates a nested operation: first a percentage of a number, then a square root. Compute in the correct order to avoid mistakes, turning the percentage into a decimal multiplier and then taking the square root exactly.Given Data / Assumptions:
- Percent = 3.6% = 0.036.
- Number = 40.
Concept / Approach:Compute 3.6% of 40 as 0.036 * 40. Then take √ of the result. Recognize perfect decimal squares to simplify mental calculation (1.44 has square root 1.2).Step-by-Step Solution:
3.6% of 40 = 0.036 * 40 = 1.44.√(1.44) = 1.2.Verification / Alternative check:Note 12^2 = 144, so (1.2)^2 = 1.44. Thus the square root of 1.44 is precisely 1.2; no rounding necessary.
Why Other Options Are Wrong:
- 2.8 and 1.8: Do not square to 1.44; they are far from the correct square root.
- None of these: Not needed since 1.2 is exact and listed.
Common Pitfalls:Treating 3.6% as 0.36 or 3.6 (misplacing the decimal), or taking the square root before computing the percentage.
Final Answer:
1.2