unity – How to instantiate cubes at every given positions

I have a list of coordinates in 3D (XYZ)

list = {{226.29, 485.28, 345.396}, {298.292, 108.226, 551.422},
{452.987, 164.874, 416.242}, {562.8, 29.4951, 297.651},{-610.087, -99.9056, -156.377},
{470.804, 12.3284, 428.671}, {590.609, 197.615, -137.146}}

I want to instantiate cubes at every given positions,
how to define given list correctly in C# and use it as a vector3 ?

I tried something like that..

    for (int i = 0; i < 7; i++)
    {
        Instantiate(prefab, new Vector3(list(i)), Quaternion.identity);
    }