Multiple choice general knowledge square root of 0.4 0.72 0.61 0.636 0.2 Reveal answer Fill a bubble to check yourself C Correct answer Explanation √0.4 ≈ 0.6325. Among the options, 0.636 is closest: 0.636² = 0.4045 ≈ 0.4. Option B (0.61) gives 0.61² = 0.3721, which is less accurate.