10,11,12

ete 10. Suppose that events E and F are independent, P(E) = 0.25, and P(F) = 0.7. What is the P(E and F) ? 11. A test to determine whether a certain antibody is present is 99.9% effective. This means that the test will accurately come back negative if the antibody is not present (in the test subject) 99.9% of the time. The probability of a test coming back positive when the antibody is not present (a false positive) is 0.001. Suppose the test is given to four randomly selected people who do not have the antibody. a) What is the probability that the test comes back negative for all four people? b) What is the probability that the test comes back positive for at least one of the four people? 12. The probability that a randomly selected 5-year-old male chipmunk will live to be 6 years old is 0.983. a What is the probability that six randomly selected 5-year-old male chipmunk will live to be 6 years old? years old? b) What is the probability that at least one of six randomly selected 5-year-old male chipmunks will not live to be 6 c) Would it be unusual if at least one of five randomly selected 5-year-old male chipmunks did not live to be 6 years old