A bottling company needs to produce bottles that will hold 12 ounces of liquid for a local brewery. Periodically, the company gets complaints that their bottles are not holding enough liquid. To test this claim, the bottling company randomly samples 15 bottles and finds the average amount of liquid held by the 15 bottles is 11.80 ounces with a standard deviation of 0.2 ounces. Calculate the appropriate test statistic. at