Question 1203267
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Although the statement of the problem is, in fact, deficient, as the other tutor says, don't take her unnecessary snide comments personally.  You have probably stated the problem exactly as it was given to you.<br>
One simple interpretation of the problem is that, since the probability of success is 80%, the probability of a failure is 20%.<br>
Given that the statement of the problem says the procedure was performed 5 times, very likely the intent of the problem is to find the probability that there is AT LEAST one failure among the five procedures.<br>
Then the answer is 1, minus the probability that all five procedures are successful.<br>
{{{1-(4/5)^5=1024/3125=2101/3125}}}<br>
ANSWER: 2101/3125, or 67.232%<br>