SOLUTION: The Better Business Bureau reported that approximately 72.2% of consumer complaints in 2006 were settled. If a random sample of five consumer complaints is selected, what is the

Algebra ->  Probability-and-statistics -> SOLUTION: The Better Business Bureau reported that approximately 72.2% of consumer complaints in 2006 were settled. If a random sample of five consumer complaints is selected, what is the      Log On


   

Question 421078: The Better Business Bureau reported that approximately 72.2% of consumer complaints in 2006 were settled.
If a random sample of five consumer complaints is selected, what is the probability that at least one was not settled? At least one was settled?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The Better Business Bureau reported that approximately 72.2% of consumer complaints in 2006 were settled.
-------
If a random sample of five consumer complaints is selected,
---
Binomial Problem with n = 5
p(settled) = 0.722
p(not settled) = 0.278
--------
what is the probability that at least one was not settled?
P(at least one was not settled) = 1 - P(all were settled of 7225)
= 1 - (0.722)^5
---
= 1 - 0.1962
---
= 0.8038
==============
Cheers,
Stan H.

====================
At least one was settled?
P(at least one settled) = 1 - P(none settled of 5)
= 1 - (0.278)^5
---
= 1 - 0.001660
= 0.99834..