THE STATISTICAL DISTANCE
Before we look at the concept of statistical distance, it is worth pointing out first what is meant by distance in mathematics. Definition Suppose that V is a non-empty set and d is a function from V×V to .Read More
THE QUARTILES
While the median splits data into two groups with an equal number of data, the quartiles separate them into four groups with an equal number of data. If a set of data has Q1 as its first quartile and Q3Read More
THE MEDIAN
In the article Introduction to The Measures in Statistics, it is stated that there are several measures of location such as the mean, median, mode, etc. The article also warns us not to apply the mean if the data beingRead More
FINDING VARIANCES WITHOUT CALCULATING MEANS
Suppose that we have collected some sample data and presented them in a frequency distribution table with equal class widths, As a consequence, we can apply the coding method to calculate the variance. By this method, the variance can beRead More
POPULATION PRINCIPAL COMPONENTS
A principal component analysis is concerned with explaining the variance-covariance structure of a set of variables through a few linear combinations of these variables. Hereinafter, each linear combination is referred to as a component. The number of components can beRead More
APPLICATION OF DERIVATIVES IN OPTIMIZATION IN BUSINESS
This post presents some examples of how the derivatives are applied in optimization in business. Example 1: (Minimizing Average Cost) In the making of some product, the total cost is TC = $(0.4Q2 + 500Q + 16000). How manyRead More
SQUARE-ROOT MATRICES
Suppose that X and A are matrices and A is positive definite. (A is a positive definite matrix if x’Ax > 0 for every nonzero vector x.) The matrix X is called the square-root of A if X2 = A.Read More
RANK CORRELATION COEFFICIENT
Is there a significant relationship between ones’ education level and their public speaking skill? Is there a correlation between TOEFL scores and the ability to speak in English? Is there any relatedness between the alumni’s GPAs and their linguistic intelligence?Read More
THE ANATOMY OF FREQUENCY DISTRIBUTION TABLES
Quantitative data can be presented in the form of frequency distribution tables. Here is a typical frequency distribution table (FDT). Table 1 shows the duration of 20 conversations. There are five classes (or categories) for the duration. Each class isRead More