A random sample of 16 pharmacy customers showed the waiting times below (in minutes). 21 28 20 16 13 19 30 22 16 18 19 23 17 20 22 23 Click here for the Excel Data File 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.) The 90% confidence interval 18.530 to 22.347 es