how do you find confidence interval value when $sigma$ is unknown how to estimate the length of a confidence interval if a confidence interval is unknown, what should it be what is the expected cci? when a confidence interval is unknown, how to find the confidence interval of $sigma if $sigma$ is a value of confidence in a normal distribution, what is the expected value of the confidence interval? is sigma a normal statistic how to find a confidence interval what is the expected value of the length of the confidence interval how to calculate confidence interval x what is the expectation of the length of the confidence interval what is expected value of the length of a confidence interval? how to find the confidence interval what is expectation in the confidence interval what is the expected value of a confidence interval? how to find the expected value of the length of a confidence interval in a linear logistic regression analysis confidence interval of length when confidence interval is unknown how to find how to measure a confidence interval if sigma is unknown what is the expected value of the confidence interval