How to Calculate Standard Deviation for Defective Bolts?

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The discussion centers on calculating the standard deviation of defective bolts, given a probability of 1/10 and a sample size of 400 bolts, resulting in a mean of 40 defective bolts. Participants emphasize the importance of attempting a solution to adhere to forum rules. There is a lack of initial solutions provided, with one participant expressing confusion about the topic. The conversation highlights the need for clarity in problem statements and calculations. Overall, the thread reflects challenges in understanding standard deviation in the context of defective items.
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1. The problem statement,
The probability of a defective bolt is 1/10. Find the standard deviation of defective bolts of a normally distributed set of 400 bolts.
and given/known data
Mean = 40 bolts
2. The attempt at a solution
None
 
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moonman239 said:
1. The problem statement,
The probability of a defective bolt is 1/10. Find the standard deviation of defective bolts of a normally distributed set of 400 bolts.
and given/known data
Mean = 40 bolts
2. The attempt at a solution
None
Per the forum rules, you must make an attempt at a solution.
 
Mark44 said:
Per the forum rules, you must make an attempt at a solution.

I can't even think of one, but I'll post one as soon as I can.
 
Oooohhhh, wrong title. Argh.
 

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