1. A certain kind of packaged food bears the following statement on the package: "Average net weight 12 oz." A consumer group has been receiving complaints from users of the product who believe that they are getting smaller quantities than the manufacturer states on the package. A random sample of 144 packages of the food product is collected, and it is found that the average net weight in the sample is 11.6 oz. and the sample standard deviation is 6 oz. Is there evidence that the manufacturer is under filling the packages. Use = 0.01.