a rare eye cancer. There were suspicions that it could have been due to exposure to a chemical used at a local distillery. A well-defined case control study in the town revealed of the 110 identified cases of this eye cancer, 80 had been exposed to the chemical. In the control group of 330 randomly selected people from within the study base, 40 had been exposed to the chemical.
Of the total number of cases of the rare eye cancer in the community, what proportion can be attributed to exposure to the chemical?