Find the fourth proportional to 5, 9, 12, ….
Find the fourth proportional to 5, 9, 12, ….
[A]21.3
[B]21.6
[C]20.16
[D]20.06
21.6
Let the fourth proportional to 5, 9, 12 be x.
Then 5:9::12:x<=>$latex 5\times x=9\times 12 $
$latex =>x=\frac{9\times 12}{5}=21.6&s=2$
Hence the fourth proportional to 5, 9, 12 is 21.6
