Measuring Central Tendency and Variability - Essay Example

There are three measures of Central Tendencies, the most used being Mean which looks at the score of all the variables and creates an arithmetic average. Therefore the count of blue shirts sold against other colors would be annualized and an average taken with the same equation for all other variables. Median divides the sets of data in half and places half above the median and half below the median while mode pertains to the score that occurs more frequently in a set of data. In each case, an entire set of data can be summarized with a single value.

There are also three main formulas for the measure of variability and they are Range, Variance, and Standard Deviation. Through these measures, we can tell how much the data in each set varies. Range measures the distance between the highest and lowest values and gives us an idea of the width of our data set. This is popular although it does not show where the data is grouped in the set. The total amount of variability is taken into account with Variance. To assess the difference in data sets a point needs to be found to which each observation can be compared. As the mean takes in every observation in its calculation it would be the best point of comparison. Standard Deviation calculates the square root of variance. It gives a good measure of variance and shows the average distance each observation is from the mean.