Walmart has received numerous customer complaints regarding the timeliness of their online orders. You are working in operations management for Walmart and are tasked with checking if these complaints are warranted. First, you decide to examine all the orders for those who purchased guaranteed two-day (48 hour) shipping. Since customers would not complain about early deliveries, you decided to test whether packages are arriving past or later than the 48-hour window. You pull company data on the 150 most recent deliveries and find an average delivery time of 48.62 hours and standard deviation of 3.85 hours.