quote:
Originally posted by John Anderton
I still aint clear about the question
Then don't post......
quote:
Originally posted by absorbation
0.6*0.1? If I am not right I have failed my statistics GCSE last Thursday .
I think you failed
quote:
Originally posted by Reload2
It should be: 1/10*1/10*1/10*9/10*9/10=81/100000
No that is not quite right.... Lets call a success A(1/10) and a failure B(9/10). This equation above would be the probability of AAABB and not the probability of having 3 successes out of 5. You must consider all of the possibilities- AAABB AABAB AABBA ABAAB ABABA ABBAA BAAAB BAABA BABAA BBAAA
There are 10 possible different ways which you can have 3 successes and 2 failures. An easier way to find this number is just by multiplying 5(number of trials) by 2(number of failure/successes, whichever is the smaller number). Each of the 10 possible outcomes above all have the same probability of occuring and that probability is 1/10*1/10*1/10*9/10*9/10=81/100000 so 81/100000*10= 81/10000 or .81% chance
The formula would be...
(probability of successes^number of successes)*(probablility of failure^number of failures)*number of trials*(number of failure/successes, whichever is the smaller number)
* Grue hopes he is remembering his statistics right