EXAMPLE 6.15 Have We Reduced Processing Time?

Your company hopes to reduce the mean time required to process customer orders. At present, this mean is 3.8 days. You study the process and eliminate some unnecessary steps. Did you succeed in decreasing the average processing time? You hope to show that the mean is now less than 3.8 days, so the alternative hypothesis is one-sided, . The null hypothesis is as usual the “no-change” value, days.