Measures of centerAlthough looking at graphs such as bart charts or histograms is very useful to analyze data, it is not enough in many cases in order to draw meaningful conclusions.
We also need measures of central tendency, measures of variation, and measures of position. A measure of center is the value in the middle of a data set. This value in the middle is also called average.
To find the average, you can look for the mean, the median, the mode, or the midrange.
The measure of variation refers to how close the values are to each other. The standard deviation and Chebyshev’s theorem are used a lot to find measures of variation.
The measure of position determines the position of a single value in relation to other values in the data set. Some measures of position are quartiles, deciles percentiles, percentile rank, and z scores.