Statistics

12. The NIH is creating a test for the Covid virus. The incidence of a Covid is low, 8 percent in the general population. There is a trial version, but it sometimes misses the disease. The probability of a false negative is 3 percent. Similarly, someone who does not have Covid, will sometimes get a positive reading. The probability of this is 20 percent. Fill in the tree diagram and ... Answer in percent to 2 decimal places. Marginal Conditional Probabilities Probabilities Joint Probabilities P(positive | D) P(D and positive) 196 False negative P(D) P(negative | D) P(D and negative) False Positive P(no D) P(positive | no D) P(no D and positive) P(negative | no D) P(no D and negative) Calculate the probability that a positive test result means someone has Covid. 13. In a survey of 242 professional athletes, it was found that 124 of them owned a convertible, 94 of them owned a giant screen TV, and 105 owned a sporting goods store. 21 owned a convertible and a store, 34 owned a TV and a store, and 55 owned a covertible and a TV. 11 owned all three items. 1. How many athletes did not own any of the three items? 2. How many owned a covertible and a TV, but not a store? 3. How many athletes owned a convertible or a TV? 4. How many athletes owned exactly one type of item in the survey? 5. How many athletes owned at least one type of item in the survey? 6. How many owned a TV or a store, but not a convertible? A certain disease has an incidence rate of 0.6%. If the false negative rate is 8% and the false positive rate is 3%, compute the probability that a person who tests positive actually has the disease