• March 12th 2006, 10:15 AM
Jon
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• March 12th 2006, 03:50 PM
ThePerfectHacker
Quote:

Originally Posted by Jon
A machine is producing parts that on average have a .05 probability of being defective. If a random sample of 5 parts is selected and each part is tested, finding the following probabilities:

getting exactly 1 defective part
getting no defective part
getting at most 1 defective part
getting at least 1 defective part
getting 5 defective parts

Use the formula:
If the probability of an event is $p$ then the probability of that event happening $m$ out of $n$ times is,
$_nC_mp^n(1-p)^{n-m}$

In the problems when they are for at most. You need to add up all the probabilities. For example, at most 3: which means probability of exactly 0 plus probability of exactly 1 plus probability of exactly 2 plus probability of exactly 3.

The same with at least only in the other direction.