Excel: Spread – Z-Scores

Leveraging Z-Score to Understand Data Dispersion In my Standard Deviation article I demonstrated how to use the squared variance to show the average distance each data point resides from the mean. While variance and standard deviation illustrate data dispersion from the mean in terms of their precise location in relation to the mean, Z-Score provides…

Statistics: Distributions – The empirical rule

Statistics: Distributions – The Empirical Rule In my Distribution Shapes article, I discussed the different shapes most distributions of data would visually utilized, with symmetrical being the most common. These bell-shaped distributions demonstrate the “empirical rule” which demonstrates a relationship between data points and standard deviations placement in relation to the mean. The distribution below…

Statistics: Distribution Outliers

Understanding Causes of Skewed Distribution Shapes In my Distribution Shapes article I illustrates the three most common shapes founds with distributions – symmetrical, left-skewed, and right-skewed. Symmetrical distributions display data points equally on both sides because most of the values reside near the mean (average). This near-uniformity of data points with the average prevents the…

Statistics: Distributions – Conditional

Isolating Patterns Based on Conditions In my Marginal Distributions article, I illustrated how to leverage a data set to isolate two marginal distributions in comparison with the grand total of all distributions, to arrive at specific distributions. This concept illustrates the concept of a conditional distribution in that a distribution is isolated based on a…