- Thread starter
- #1

For exapmple:

I don't know the population size. I take a sample of 10 and check for a particular characteristic. Let's say number of successes for this sample is x. So the proportion of successes is x/n. Then I repeat this process 3 times. That means I take 3 samples. Then I'll calculate the mean of the x/n for these 3 samples. So how do I calculate standard deviation or standard error for this mean value?

Eg: Sample 1 => x/n = x/10 =3/10 =30%

When this is done to all three samples,

Sample 1 => 30% +- a

Sample 2 => 32% +-b

Sample 3 => 32% +- c

Mean = 31.33% +-d

How do I calculate a,b,c and d? And what if I have different sample sizes for the three occasions? (having 10, 15, 8 instead of 10,10,10).

Thank you very much for your help