Question

12,15,17 are in continued proportion​

Answer 1

Three quantities are said to be in continued proportion; if the ratio between the first and the second is equal to the ratio between the second and the third.

Suppose, if we have three qualities such that the ratio of first to second is equal to the ratio of second to third, we say that the three qualities are in continued proportion. The middle term is called the mean proportional between the first the third terms.

i.e. a, b and c are in continued proportion, if a : b = b : c

The second quantity is called the mean proportional between the first and the third

i.e. in a : b = b : c; b is the mean proportional between a and c.

The third quantity is called the third proportional to the first and the second

i.e. in a : b = b : c; c is the third proportional to a and b.