Author Archives: Andrew Lyon

Chi-Square Goodness-of-Fit Test

Chi-Square Goodness-of-Fit (also referred to a Pearson’s Chi-Square Test) is a statistical method for determining how an actual or observed distribution of  categorical variables relates to a theoretical distribution of those same variables. The Chi-Square Test is a non-parametric test meaning that its graph is not expected to approximate a normal distribution curve.  An example […]


The Median is the middle of a ordered distribution of a sample, range, population, or simply list of numbers or values. When this distribution has an odd number of terms, the median is the middle most value. If the number set is even then the median is the mean of the two middle values.  In contrast to the mean, […]

Bar Graphs

A Bar Graph is a method of displaying and comparing discrete data sets. Bar graphs display categories as rectangles whose height (if vertically displayed) or length (if horizontally displayed) are proportional to each other by the proportionality of the data they are displaying. The graph shown displays the number of dog owners per breed in a sample with a […]