What is the value of x? Enter your answer, as a decimal rounded to the nearest tenth, in the box.

Two quadrilaterals. First quadrilateral has one angle which has 1 arc, two opposite angles which have two arcs each, and the fourth angle, which is opposite the angle with 1 arc, has 3 arcs. The two sides that are each between the angle with 1 arc and an angle with 2 arcs are each labeled 18 centimeters. The two sides that are each between the angle with 3 arcs and an angle with 2 arcs are each labeled 22 centimeters. The second quadrilateral also has one angle which has 1 arc, two opposite angles which have two arcs each, and the fourth angle, which is opposite the angle with 1 arc, has 3 arcs. A side between the angle with 1 arc and an angle with 2 arcs is labeled 15 centimeters. A side between the angle with 3 arcs and an angle with 2 arcs is labeled x centimeters.