How do I calculate whether a value is significantly different from a random distribution?

I have a data set of 1,000 randomly generated values, most of which hover around a particular mean (say 0.1). I then have a single actual value generated that I wish to compare with the other 1,000 to see if it's significantly different from those 1,000, and to what extent (p-value). How do I do this and what test would I use? Thanks.How do I calculate whether a value is significantly different from a random distribution?
You will need to specify which distribution those 1000 random numbers were generated from.