Answer to Question #190080 in Statistics and Probability for Ephraim Chipilipil

Question

Which is shorter, a 95% z-interval for the mean or a 95% t-interval for the mean? Is one of these always shorter, or does the outcome depend on the sample

Answer 1

Since t-critical is greater than z-critical value, the 95 percent confidence interval for mean is shorter. Since the t-critical value cannot be smaller than the z-critical value, the z-interval is often shorter.