In: Statistics and Probability
How does the length of the 95% t confidence interval compare with that of the 95% z confidence interval? Very confused on this
The length of the 95% t confidence interval is always greater than or equal to the 95% z confidence interval.
If the sample size is very small, then the length of the 95% t confidence interval will be greater than the 95% z confidence interval.
As we increase sample size, the length of the 95% t confidence interval will be decrease.
For very large sample size, the length of the 95% t confidence interval and 95% z confidence interval will be approximately same.
For example, for sample size n = 10,000, both confidence intervals will be same. There length of the both confidence intervals will be same.
But, for sample size of n = 10, there will be bigger difference in the both intervals.