I'm SO confused. I'm still working on this problem?
4. A survey at SRA of 125 workers showed that 75 of them belonged to a union. A similar survey taken at Columbia Nitrogen showed that of 100 workers questioned 38 were union members. Develop a 95% confidence interval for the true difference between the proportions of union members.
I found out everything but how do You find out exactly what the znumber is? How do you know when you use the t table? Iwas never taught this. do i look at the mean or just the 95/2= and then do that then what?
4. A survey at SRA of 125 workers showed that 75 of them belonged to a union. A similar survey taken at Columbia Nitrogen showed that of 100 workers questioned 38 were union members. Develop a 95% confidence interval for the true difference between the proportions of union members.
I found out everything but how do You find out exactly what the znumber is? How do you know when you use the t table? Iwas never taught this. do i look at the mean or just the 95/2= and then do that then what?