Confidence interval question: I have a total of 3500 houses. I sampled 350 (10%) and found only 1 had a positive response....

[Keith000001]

I have a total of 3500 houses. I sampled 350 (10%) and found only 1 had a positive response. I am attempting to draw a conclusion as to what my confidence interval would be. I am looking for insight on how to calculate the CI so that I can apply this to other real world situations where the answer is either yes or no. Formulas used etc.

This isn't for school, but work on an inventory. So far as the inventory, I am trying to figure out how much sampling I need to do to get better than 95% CI.

 

[BigBeachBanana]

I have a total of 3500 houses. I sampled 350 (10%) and found only 1 had a positive response. I am attempting to draw a conclusion as to what my confidence interval would be. I am looking for insight on how to calculate the CI so that I can apply this to other real world situations where the answer is either yes or no. Formulas used etc.

This isn't for school, but work on an inventory. So far as the inventory, I am trying to figure out how much sampling I need to do to get better than 95% CI.

What do you mean by "better"?