Sun 9 Dec, 2012 10:23 am
An oil company is planning to drill three exploratory wells in different areas. The company estimates that each of these wells, independent of the others, has about a 30% chance of being successful.
1. Find the probability distribution of X; the number of oil wells that will be successful
2. suppose the first well is successful. what is the probability that one of the tow remaining wells is successful
@fmaella,
1)
0: 0.7^3
1: 3 * 0.3 * 0.7^2
2: 3 * 0.3^2 * 0.7
3: 0.3^3
2)
First well being successful is irrelevant.
Exactly one: 2 * 0.3 * 0.7
At least one: 1 - 0.7^2
@fmaella,
The relevance of the information that the first well is successful is that, given the events are independent, the calculation of the probability of the remaining two wells being successful is calculated without reference to the first well (ie. it is not dependent on what happened before; it is not a conditional probability).
@solipsister,
I would say that the independence of the events (which is the relevant information) makes the success of the first well irrelevant.
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