If you want to use one of the values from the array then you can do this (don't store floats in array as strings):
PHP Code:
new const Float:position[] =
{
0.55,
0.60,
0.50
}
set_hudmessage(255, 0, 0, 0.08, position[random(sizeof(position))], 0, 6.0, 2.0)
show_hudmessage(id, "test")
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