In proportional sequences, the number by which a term in the first sequence has to be multiplied to obtain the term with the same rank in the second sequence.

The coefficient of proportionality is equal to the inverse of the constant of proportionality.

### Example

Consider the following proportional sequences :

Sequence A | 2 | 4 | 6 | 8 | 10 | 12 | × 3.5 |

Sequence B | 7 | 14 | 31 | 28 | 35 | 42 |

In this case, the coefficient of proportionality is 3.5.