Good morning everyone,
I have a question in regards to Statistically Significant Sample Sizes to a population. I am working with data in excel and wanting to put the formula for this into the workbook as well but have run into a roadblock of sorts. I am probably over thinking it but have been stumped on this one last piece for over a day now and my google searching has not helped much either. But anyway to the problem at hand and I would greatly appreciate any assitance.
I have two data elements - N and n - Population and sample size, I did all the other items that were asked and thought I had this one as wel but then got stumped. I want/need to know if the sample size being performed is statistically significant to the population. So to start off I just did a normal sample size calculator where the population isn't needed. I used a 90% Confidence Level, a standard deviation of 0.5, and I used a 5% confidence interval. When using this it shows that the sample size was significant but here is where the problem lies. There are 6 categories in the over arching population and if you break the population into their catgories none fo those sample sizes are significant individually, so I am wanting to be able to use the population (N) as a reference point for statistically significance. And that is where I am stumped. Here is an example of the numbers: Lets say the population is 200,000 orders and the QA department audited 700 of those orders for accuaracy - is 700 a statistically sinificant amount to the population. When I use a simple sample size calculation it says that the sample size needs to be around 300 which does show that the 700 is sufficient but when i break that population and sample into the subcategories - north, south, east, west, central and international where the most one of these categoires has is 250 audits and 90,000 population the sample size calculation shows that this number is not significant because the calculation I used doesnt take populatin size into account.
I know this is long but i was just trying to explain everything as clear as I could. Any help that can be given would be greatly appreciated.
Thanks
I have a question in regards to Statistically Significant Sample Sizes to a population. I am working with data in excel and wanting to put the formula for this into the workbook as well but have run into a roadblock of sorts. I am probably over thinking it but have been stumped on this one last piece for over a day now and my google searching has not helped much either. But anyway to the problem at hand and I would greatly appreciate any assitance.
I have two data elements - N and n - Population and sample size, I did all the other items that were asked and thought I had this one as wel but then got stumped. I want/need to know if the sample size being performed is statistically significant to the population. So to start off I just did a normal sample size calculator where the population isn't needed. I used a 90% Confidence Level, a standard deviation of 0.5, and I used a 5% confidence interval. When using this it shows that the sample size was significant but here is where the problem lies. There are 6 categories in the over arching population and if you break the population into their catgories none fo those sample sizes are significant individually, so I am wanting to be able to use the population (N) as a reference point for statistically significance. And that is where I am stumped. Here is an example of the numbers: Lets say the population is 200,000 orders and the QA department audited 700 of those orders for accuaracy - is 700 a statistically sinificant amount to the population. When I use a simple sample size calculation it says that the sample size needs to be around 300 which does show that the 700 is sufficient but when i break that population and sample into the subcategories - north, south, east, west, central and international where the most one of these categoires has is 250 audits and 90,000 population the sample size calculation shows that this number is not significant because the calculation I used doesnt take populatin size into account.
I know this is long but i was just trying to explain everything as clear as I could. Any help that can be given would be greatly appreciated.
Thanks
