The fourth proportional to 5, 8, 15 is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 24
The fourth proportional to \(a\), \(b\), \(c\) is the number \(x\) that makes \(a:b=c:x\), so the product of the extremes equals the product of the means: \(ax=bc\).
\(5:8=15:x\)
\(5x=8\times15=120\)
\(x=24\)