Question

If 9, x and 81 are in continued proportion, find x.
If 28, 42 and y are in continued proportion, find y​

Answer 1

Answer:

If a,b,c are in continued proportion, then b/a=c/b or b²=ac or b=√(ac)

In first case, 9,x,81 are in continued proportion. so x=√(9*81) = 3*9 =27

In second case, 28,42,y are in continued proportion. So y/42 = 42/28.

Or, y = 42 * 3/2 = 21*3 = 63.

Therefore, x=27 and y=63.