Author Archives: Matt Wentzel

Confidence Interval for Paired Means

The method of paired means is used when two sets of data have the same number of elements, and there exists a one-to-one correspondence between the elements of each set. The first step in using this method is to calculate the difference between the two sets of data: . This results in one quantitative variable […]


The mean, also referred to as average, of a set of data is the sum of all the data elements divided by the total number of elements. As a mathematical equation it is represented as, , where y represents the data elements and n represents the total number of data elements. In descriptive statistics there are two […]

Clustered Bar Graphs

A clustered bar graph is a type of bar graph that allows for the display of two categorical variables. Like the typical bar graph it compares data from a sample that pertains to specific categories or attributes of a categorical variable to another property, usually a frequency, about those given attributes. The clustered effect allows […]