QUESTION 11 Suppose P(A) = 0.45. The probability of complement of A is: O a. 0.35 O b. 0.45 O c. 0.55 O d. 0.75 O e. None of the above QUESTION 12 Brisbane City Council finds that it is cost-efficient to replace all street-light bulbs at once, rather than to replace the bulbs individually as they burn out. Assume that the lifetime of a bulb is normally distributed, with a mean of 2,500 hours and a standard deviation of 100 hours. If the city council wants no more than 49% of the bulbs to burn out before they are replaced, after how many hours should all of the bulbs be replaced? O a. 1,735.63 hours O b. 2,324.93 hours O c. 2,535.73 hours O d. 2,655.05 hours O e. None of the above QUESTION 13 Four PhD graduates are applying for a lectureship position in a college. The four applicants are Adam, Bob, Charles and Derek. Employing the subjective approach, Jerry has assigned the following probabilities that these applicants will be hired: P(Adam) = 0.41 P(Bob) = 0.10 P(Charles) = 0.27 P(Derek) = 0.22 The probability that either Bob or Charles are hired is: O a. 0.10 O b. 0.17 O c. 0.27 O d. 0.37 O e. None of the above