Solving a real world problem with hypothesis testing for a z scores for distribution of sample means. This lesson is posted under a Creative Commons license: http://creativecommons.org/licenses/by-nc-sa/3.0/ Content may be used for educational purposes with an attribution to: Michelle Samuel, Mount St. Mary's College (2013). Not for commercial purposes. If you alter or build upon this work, you may distribute the resulting work only under the same license as this one.