2. A company produces antidote injection vials. Suppose the probability to have a defective vial is 1 per 5000 vials:

(a) If 5 vials are randomly selected,
i. what is the average number of vials you expect to be defective?
ii. what is the probability that at least one of them is defective?
(b) If 10,000 vials are randomly selected, (think of this as an 'area of opportunity')
i. what is the average number of vials you expect to be defective?
ii. what is the probability that at least one of them is defective?

Question

2. A company produces antidote injection vials. Suppose the probability to have a defective vial is 1 per 5000 vials:  

(a) If 5 vials are randomly selected,
	i.	what is the average number of vials you expect to be defective?
	ii.	what is the probability that at least one of them is defective?
(b) If 10,000 vials are randomly selected, (think of this as an 'area of opportunity')
	i.	what is the average number of vials you expect to be defective?
	ii.	what is the probability that at least one of them is defective?

anonymous · Answer

FOR (a) its Binomial distribution
FOR (b) its NORMAL distribution

anonymous · Answer

Does it help?

allank · Answer

Well, you could think about it logically: The probability to have a defective vial is 1 per 5000 vials. Thus the probability that any given vial picked is defective is 1/5000.
a) If 5 vials are selected, the total probability of being defective is 5*1/5000=1/1000. Thus we expect 1/1000 of the 5 vials to be defective. Thus i) 1/1000