A random sample of 16 pharmacy customers showed the waiting times below (in minutes). 18 23 20 15 24 22 25 17 26 11 19 25 23 17 21 22 Find a 90 percent confidence interval for , assuming that the sample is from a normal population. (Round your standard deviation answer to 4 decimal places and t-value to 3 decimal places. Round your answers to 3 decimal places.) Sample The 90% confidence interval ? to