Problem: One study has evaluated a number of leukaemia records in a rural area. The population of the area was 35,000. In a year there were 12 leukaemia cases identified. In the general population like this, the annual rate of leukaemia is about one in 10,000. Was it evidence of a problem in the area, or was it a chance? Can you verify this? Would Binomial or Poisson distribution be suitable for modeling this case?