Question

Civil Engineering System ** PLEASE HELP WITH THE HIGHLIGHTED PROBLEMS ONLY ( 15 & 19 )

equal to 10. c. As more and more items are sampled, the propor All the fourth-graders in a certain elementary school took a standardized test. A total of 85% of the students were found to be proficient in reading, 78% were found to be proficient in mathematics, and 65% were found to be proficient in both reading and mathematics. A student is chosen at random. tion of defective items will approach 10% 11. A quality-control engineer samples 100 items manu- nds that 15 of them factured by a certain process, and fi are defective. True or false a. The probability that an item produced by this pro- a. What is the probability that the student is proficient cess is defective is 0.15 in mathematics but not in reading? b. b. The probability that an item produced by this pro- What is the probability that the student is proficient cess is defective is likely to be close to 0.15, but not exactly equal to 0.15 in reading but not in mathematics? c. Whatis the probability that the student is proficient in neither reading nor mathematics? 12. Let V be the event that a computer contains a virus, event that a computer contains a and let W be the worm. Suppose P(V)0.15, P(W)0.05, and P(V UW) 0.17 a. Find the probability that the computer contains 16. A system contains two components, A and B. The sys- tem will function so long as either A or B functions. The probability that A functions is 0.95, the probabil- ity that B functions is 0.90, and the probability that both function is 0.88. What is the probability that the system functions? both a virus and a worm. Find the probability that the computer contains ther a virus nor a worm. b. nei- 64 Civil Engineering Systems 62 CHAPTER 2 Probability True or false: If A and B are mutually exclusive, a. P(AUB)0 17. A system contains two components, A and B. The system will function only if both components func tion. The probability that A functions is 0.98, the probability that B functions is 0.95, and the proba- bility that either A or B functions is 0.99. What is the probability that the system functions? d. P(AU B) P(A) + P(B)

Answer 1

IS R- reading o. 85-0, 65 0.98 98% -I-0.9): 0.01-2%

19) For two mutually exclusive events, P(A  B) = 0

P (A B) = P(A) + P(B)