For instance, one, two, three, being given, everyone can see that the fourth proportional is six; and this is much clearer, because we infer the fourth number from an intuitive grasping of the ratio, which the first bears to the second.
Baina zenbaki sinpleenentzat ez da horren beharrik: hala nola, 1. 2. 3. zenbakiak emanez geroz, nornahik ikus dezake laugarren zenbaki proportzionala 6 dela;