In this free online video, students discover an improved technique for statistical problems that involves a population mean: the t statistic for use when sigma is not known. Emphasis is on paired samples and the t confidence test and interval. The program covers the precautions associated with these robust t procedures, along with their distribution characteristics and broad applications." This individual video is accessed by scrolling down to the "Individual Program Descriptions - 21. Inference for One Mean" and click the "VOD" icon at the top-right of the description.