Fill out the 2 by 2 table below on an imaginary set of 10,000 blood samples, using the three numerical facts in the previous paragraph. Start with the 1% figure and fill the table in from there, explaining as you go.

                                    The Truth
                            person    | person does
                            has  AIDS | not have AIDS
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What ELISA  ELISA positive |          |              |
says        ELISA negative |          |              |
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                                                     | 10,000