Interview Question 3: Random number generator with weights

Generate random numbers such that they follow certain needed pattern. For example out of 100 generated random numbers.

35% should be    5
20% should be   25
10% should be   123
35% should be   73

The naming is confusing. The set of output numbers is small. You are just creating numbers from a small set {5,25,123,73} but the sequence of output numbers is random or unpredictable.

Can you think of any application or test bench mechanism where such numbers are needed?