disease or infection y à aiiure is due to Problem 2.113 from textbook (6th editi

Question

disease or infection y à aiiure is due to Problem 2.113 from textbook (6th edition): (10pts) A batch of 30 injection-molded parts contains 6 parts that have suffered excessive shrinkage. a) If two parts are selected at random, and without replacement, what is the probability that the second part selected is one with excessive shrinkage? b) If three parts are selected at random, and without replacement, what is the probability that the third part selected is one with excessive shrinkage? Problem #4 (15pts) A firm has ordered a batch of identical electronic device from 4 different suppliers with the following distribution: 30% supplier 1, 20% supplier 2, 35% supplier 3, and 15% supplier 4. The historical data shows that 8% of supplier l items, 6% of supplier 2 items, 4% of supplier 3 items, and 10% of supplier 4 items are defective. 1- What is the probability that a randomly selected device is coming from supplier 3 and is defective? If an item is selected randomly from the batch, what is the probability that the selected item is defective? 2- If an item is selected at random and it is defective, what is the probability that it is coming from supplier 3? 3-

Explanation / Answer

#2.113 a) Let S represent excessive shrinkage, then P(2nd part is S) = SS + S'S
= [(6/30)*(5/29)] + [(24/30)*(6/29)] = 0.2

b) P(3rd part is S) = SSS + S'SS + SS'S + S'S'S
= [(6/30)*(5/29)*(4/28)] + [(24/30)*(6/29)*(5/28)] + [(6/30)*(24/29)*(5/28)] + [(24/30)*(23/29)*(6/28)] = 0.2

#4 1) P(Defective | Supplier 3) = P(Supplier 3 and Defective) / P(Supplier 3)
P(Supplier3 and Defective) = 0.04 * 0.35 = 0.014

2) P(Defective) = P(Supplier1 and Defective) + P(Supplier2 and Defective) + P(Supplier3 and Defective) + P(Supplier4 and Defective) = 0.08*0.3 + 0.06*0.2 + 0.04*0.35 + 0.1*0.15 = 0.281

3) P(Supplier 3 | Defective) = P(Supplier and Defective)/ P(Defective = 0.014 / 0.281 = 0.0498

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.