how to use Z table ?
I have seen in a illustartion the the valuse Z(alpha/2) = z (.05/2) = 1.645
but i coldn’t understand how this value is drawn?
I don’t want to confuse you any more than you might be now. I am just starting to grasp probability distributions myself. I have learned to stop asking why the sky is blue and just accept that is and move on. Bernouli et al. spent there short lives thinking about this stuff for years and we are going to completely understand it in 8 weeks? I have my doubts.
Check out this link and see if it helps you: