First, consider deliberate thinking. Deliberate thinking is relatively slow, rule-based and explicit; a contemplative process of weighing pros and cons, gathering scientific or statistical evidence. It would appear that this makes for pretty solid decision-making.
Jul 24, 2015. Outliers increase the standard deviation. Mean is most affected by outliers, since all values in a sample are given the same weight when calculating mean. A value that is far removed from the mean is going to likely skew your results and increase the standard deviation. Say you have five values: 2, 1, 2, 1.5, and 2.1.
The median of these numbers is 3.5 (halfway between 3 and 4) The mean of these numbers, however, is 4.6, which is greater than the median (because of the huge outlier). Since 21 is obviously an outlier, let's remove it. The median moves from 3.5 to 3. The mean moves from 4.6 to 2.78, which is a big decrease.