Home › RRB NTPC › Quantitative Aptitude › Ratio and Proportion › Find the mean proportional between $16$ and $25$.
Find the mean proportional between $16$ and $25$.
A$18$
B$20$
C$22$
D$24$
Answer & Solution
Correct answer: B. $20$
Mean proportional $= \sqrt{a \times b} = \sqrt{16 \times 25} = \sqrt{400} = 20$.
Option A (18) is the arithmetic mean $(16+25)/2 \approx 20.5$ rounded down — close, but not the geometric mean asked for.
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