# Thread: Estimating, CI's and testing: When do you add √{ (N-n)/(N-1) } to the formula?

1. ## Estimating, CI's and testing: When do you add √{ (N-n)/(N-1) } to the formula?

Hello,

I'm new to this forum. It seems helpful! I hope I can contribute some myself as well.

But now, I'd be very glad if you could help me with my Statistics test preparation. The test will be about estimating, confidence intervals and hypothesis testing.

My question is when to use what formula (see picture). I don't understand in what case I have to add in √{ (N-n)/(N-1) } to the formula, and when I don't, for estimating, CI's and testing.

This is how it's stated on my formula paper:
http://img15.imageshack.us/img15/7224/vraag1c.png