Answer to Question #140865 in Statistics and Probability for Margaret

Question

Assume that the population standard is known to obtain a confidence interval for the population mean is reasonable to use
1. The Z-interval procedure
2. The two tall procedure
3. The t-interval procedure
4.The one-tail procedure
5. A sample size greater than 30

Answer 1

It is reasonable to use Z-interval procedure to obtain a confidence interval when the sample size is greater or equal to 30 or the distribution is normal. Thus option 1 is correct.