How Do You Calculate Samples Containing Defective Widgets?

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SUMMARY

The discussion focuses on calculating the number of samples containing defective widgets from a set of 100, where 3 are broken. The total number of samples of size 5 is established as 75,287,520. To determine how many samples contain at least one broken widget, the probability of selecting a sample with no broken widgets is calculated using the formula (97*96*95*94*93)/(100*99*98*97*96). This probability is then multiplied by the total combinations to find the number of samples without broken widgets, which can be subtracted from the total to find those that include at least one defective widget.

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I am working on a problem in which there are 100 widgets. I need to find how many samples of size 5 there are, which I found to be 75,287,520. No problem there. I am not sure how to go about the next part, however. In the original set of 100 widgets, 3 are broken. How many of the samples of 5 contain at least one of these broken widgets? No idea how to do that. Can someone please help? Thanks!
 
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The probability that a given set of 5 widgets has no broken ones is
(97*96*95*94*93)/(100*99*98*97*96). Multiply that by the total number of combinations to get the number without any broken.
 
If you want to use the basic counting formula, remove the 3 bad widgets from the set and you have 97. Calculate the number of samples of size 5 for the 97 and subtract from the number of samples of 5 for 100.
 

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