Measures of Central Tendency

The Mean, the Median, and the Mode are the most common measures of central tendency.

The mean (most properly called the arithmetic mean) is the simple average of the data: the sum of all data points divided by the number of data points.

Calculation of the mean

The median is described as the numeric value separating the higher half of a sample, a population, or a probability distribution, from the lower half. The median is the “middle value.” If there is an even number of observations, then there is no single middle value; the median is then usually defined to be the mean of the two middle values. At most, half the population has values less than the median, and, at most, half have values greater than the median. If both groups contain less than half the population, then some of the population is exactly equal to the median

The mode is simply the most frequently occurring value.

In a Normal Distribution, the mean, the median, and the mode are equal.