神马品牌网30倍望远镜能看多远:求一道英文的统计题答案!急用!谢谢!
来源：百度文库 编辑：神马品牌网 时间：2024/05/13 08:00:21
A light bulb is to be selected at random from a box of 100 bulbs. The box contains a mixture if 60 watt and 100 watt bulbs details of which are given below.
Type of bulb Defectives Satisfactory
60 watts 20 40
100 watts 10 30
Find
(i) P (selected bulb is defective)
(ii) P (selected bulb is 100 watts / selected bulb is defective)
(iii) Suppose that the company receiving the bulbs has a policy of selecting, without replacement, two bulbs from each box when it is delivered. It then applies the following decision rules:
If both bulbs are satisfactory, the box will be accepted.
If both bulbs are defective, the box is returned to the supplier.
If one bulb is defective, a third bulb is selected and the box is only accepted if this bulb is satisfactory.
Draw a probability tree representing the above outcomes and show the joint probabilities.
What is the probability that a box, referred to above, will be rejected?
Type of bulb Defectives Satisfactory
60 watts 20 40
100 watts 10 30
Find
(i) P (selected bulb is defective)
(ii) P (selected bulb is 100 watts / selected bulb is defective)
(iii) Suppose that the company receiving the bulbs has a policy of selecting, without replacement, two bulbs from each box when it is delivered. It then applies the following decision rules:
If both bulbs are satisfactory, the box will be accepted.
If both bulbs are defective, the box is returned to the supplier.
If one bulb is defective, a third bulb is selected and the box is only accepted if this bulb is satisfactory.
Draw a probability tree representing the above outcomes and show the joint probabilities.
What is the probability that a box, referred to above, will be rejected?