Random position on vector3 y between specific values

I need to spawn an enemy on random 5 differents but specified position, them are:
1° x:-1,86, y:-2,56 / 2° x:-1.86 y:-1.06 / 3° x:0 y:-1.06 / 4° x:-2 y:-2.56 / 5° x:-2 y:-1.06.
i tried to creare an array:

var x_random:float[] = [ -1,86, 0, 2 ];
var y_random:float[] = [ -2.56, -1.06 ];

and then call in in a Vector3

Instantiate (Nonnino, new Vector3 (x_random + 10.0f, y_random), Quaternion.identity);

but it doesen’t works, can someone help me?

You declared both of them as arrays of float. Then you must provide the index.

var random: int = 0;

random = Random.Range(0, 2); // Randomize the index 0, 1, 2

new Vector3 (x_random[random] + 10.0f, y_random[random])