Why must (xmean) always be equal to zero? You need to provide a mathematical explanation based upon the definition of the mean. This is an extremely important concept. The mean represents more than just adding up all values in a data set and then dividing by the total number of values in the data set. Your understanding of the mean has to rise to a new level. If you cannot answer this part, you don't understand the definition for the mean.

3. Is the mean, median, or mode most sensitive to the presence of extreme values (often referred to as outliers)? Provide a mathematical explanation to substantiate your claims. Hint: Perform some very simple mathematical calculations.