Excel generate probabilities

I have a list of users in an excel sheet. Corresponding to each user, I need to generate a column that shows the probability of some event occurring. This is a decimal number of 4 digit precision (0.1234).

I need a way to randomly generate this 4-digit precision probability column such that all the probabilities add upto 1.

I am able to do this based on percentage, but for the testing purpose that I am using this, it would be more effective if it were as stated above. Also a drawback of the method that I am using is that formula I use gives more weightage to the users at the beginning than towards the end.

IS there a better way I can achieve this in excel? What all could be good ways to achieve this?