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Statistics, probability help please !

by Calculator14
Tags: help!, probability, statistics
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Jul6-11, 12:43 PM
P: 30
1. The problem statement, all variables and given/known data

In a certain high-risk group, the chance of a person having suffered a heart attack is 70%. If four persons are chosen from the group, find the probability that at least one will have had a heart attack.

2. Relevant equations

(work shown below) these would be dependent

3. The attempt at a solution

(.7)/(4) = 2.8
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Jul6-11, 12:51 PM
P: 925
It might be easier to think of the chance that a specific individual doesn't have a heart attack, so what are the chances that none of the individuals have heart attacks (and you might want to rethink the dependence).
Jul6-11, 12:52 PM
P: 13
your answer is wrong

i don think it is a dependent event

the probability of a person with heart attack is 0.7

so the probability that among 4 at least 1 has heart attack = 1 - probability that none have

= 1 - (0.3)[itex]^{4}[/itex]

must be correct but verify it

Jul6-11, 01:25 PM
P: 6
Statistics, probability help please !

Amateur's answer is correct.

Your attempt doesn't make any sense.
Remember: probability can never be more than 1.

So if you find 2.8, think again.

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