Wisc River Falls -ECON 326 -We want to construct a 99% confidence interval for
we took a random sample of 25 customers and found a mean waiting time of 22 minutes with a standard deviation of 6 minutes. We want to construct a 99% confidence interval for the population mean of such waiting times. We know that the interval we want comes from this formula : (mean)X plus or minus (t)(s)subX. What is the value of X to be used in the formula?