# Calculating the allowed errors given sample size, accuracy required, and confidence level desired

• ### Question

• I'm stuck.  I'm not a statistics person at all and I need to determine the number of allowed errors that are allowed given a sample size value, the accuracy required, and the confidence level desired.

For example, say I have "n" transactions.  I require an accuracy of 99.90% with a 90% confidence level.  How many errors am I allowed?  (I'm expecting answers something like 2 for 5.5k transactions, 4 for 8k, 6 for 10.5k, and 12 for 15k, but I have no clue how to get there.)

In a similar fashion, if I have a sample of 5.5k transactions with 2 errors and a 90% confidence level then what is my measured accuracy?

I've perused many discussions, but have not found any that fit my more simple scenarios.  Any help will be greatly appreciated.

Regards,
Andrew

There are some ideas so preposterous that only an intellectual will believe them. - Malcolm Muggeridge

Monday, January 26, 2015 9:17 PM

• Re: inspection sampling

As Caillen Zhong pointed out this is a forum dealing with questions/issues about Microsoft Excel.

To possibly help you, do a search for Mil-Std-105e or its replacement Mil-Std-1916.
No calculations necessary, just look up the parameters in a table to determine the allowed defects.
'---
Jim Cone
Portland, Oregon USA
https://goo.gl/IUQUN2 (Dropbox)
(free & commercial excel add-ins & workbooks)

Wednesday, January 28, 2015 1:45 PM

### All replies

• Hi Andrew,

Sorry but I don't totally understand you.

This forum is actually for questions about Excel development. If you got any questions about the features or usage of Excel application, maybe Excel IT Pro Discussion forum is better. Also please describe your question clearly, some sample data or figures would better help others to understand you.

We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.

Wednesday, January 28, 2015 5:25 AM
• Re: inspection sampling

As Caillen Zhong pointed out this is a forum dealing with questions/issues about Microsoft Excel.

To possibly help you, do a search for Mil-Std-105e or its replacement Mil-Std-1916.
No calculations necessary, just look up the parameters in a table to determine the allowed defects.
'---
Jim Cone
Portland, Oregon USA
https://goo.gl/IUQUN2 (Dropbox)
(free & commercial excel add-ins & workbooks)

Wednesday, January 28, 2015 1:45 PM
• My sincere apologies for the delayed response.  I was redirected on my tasks and this just fell of my radar for a bit.

My question was both about developing a tool to use in Excel and about the business logic needed to created the tool, so I wasn't sure whether I should post here or not.

I did use the tips provided and started my search on the Mil Standards.  That led me to solutions using both the binomial and beta distribution functions in Excel.  I also found "The Handbook of Applied Acceptance Sampling" by Kenneth S. Stephens very helpful.

Thank you for the guidance.

Regards,
Andrew

There are some ideas so preposterous that only an intellectual will believe them. - Malcolm Muggeridge

Thursday, February 12, 2015 6:21 PM