Introduction to Statistics With Relevant Examples
Statistics refers to concepts, rules, and procedures that help us interpret data and make informed decisions regarding issues affecting our lives and humanity in general. Data is basically facts or observations that result from an investigation. Statistics is a wide…
Understanding a Parameter, a Statistic, and Frequency Distribution Tables
A parameter refers to a measure that is used to describe the characteristic of a population. It is a numerical quantity that describes a given aspect of the population as a whole. You should note that we are referring to…
The Relative Frequency And Cumulative Frequencies
Relative frequency refers to the percentage of observations falling within a given class. It reveals the popularity of certain classes of data based on a sample. In other words, relative frequency tells us the number of times an event occurs…
Measures of Central Tendency
Measures of central tendency are values that tend to occur at the center of a well-ordered data set. As such, some analysts call them measures of central location. Mean, median, and mode are all measures of central tendency. Even then,…
Calculating and Interpreting Quartiles, Quintiles, Deciles and Percentiles
Quartiles, quintiles, deciles, and percentiles are values or cut points that partition a finite number of observations into nearly equal-sized subsets. The number of partitions depends on the type of cut point involved.
Measures of Dispersion
Measures of dispersion are used to describe the variability or spread in a sample or population. They are usually used in conjunction with measures of central tendency such as the mean and the median. These are the range, variance,…
Chebyshev’s Inequality
Chebyshev’s inequality is a probability theorem used to characterize the dispersion or spread of data away from the mean. It was developed by a Russian mathematician called Pafnuty Chebyshev. The theorem states that:
Coefficient of Variation
The coefficient of variation, CV, is a measure of spread that describes the amount of variability of data relative toits mean. It has no units, and as such, we can use it as an alternative to the standard deviation to…
Skewness
Skewness refers to the degree of deviation from a symmetrical distribution, such as the normal distribution. A symmetrical distribution has identical shapes on either side of the mean. Distributions that are asymmetrical have unequal shapes on either side of the…
Kurtosis and Skewness
Kurtosis refers to measuring the degree to which a given distribution is more or less ‘peaked’ relative to the normal distribution. The concept of kurtosis is very useful in decision-making. In this regard, we have 3 categories of distributions:
