Position measurements

Position measurements

1. are values ​​that allow the data set to be divided into equal percentage parts and are used to classify a observation within a population or sample.

2. non-central position measures

   • the quartile
     • It is one of the most used and divides the distribution into four equal parts. Thus, there are three quartiles. The lower values of the distribution are below the first (Q1). The half or median are the smaller values ​​equal to quartile two (Q2) and the upper ones are represented by quartile three (Q3).
   • the quintile
     • Divide the distribution into five parts. So, there are four quintiles. Furthermore, there is no value that divides the distribution into two parts same. It is less frequent than the previous one.
   • the decile
     • Divide the data into ten equal parts. there are nine deciles, from D1 to D9. The D5 corresponds to the median. On the other hand, the upper and lower values (equivalent to the different quartiles) are located in intermediate points between these.
   • the percentile
     • Divide the distribution into one hundred parts. There are 99 percentiles. Have, in turn, an equivalence with deciles and quartiles.

3. Position measures are usually divided into two large groups: the trend does not center and the centers.

4. Center position measurements

   • The arithmetic, geometric or harmonic mean
     • There are three central measures that indicate an average weighted data. The first is the most used and the most acquaintance of the three The geometry is applied in series that show percentage growth. On the other hand, the harmonica It is useful in the analysis of investments in the stock market.
   • median
     • this is the most recognizable measure of central position. Divide the distribution in two equal parts. Thus, it expresses the value medium, not medium. It is very useful in variables such as income or wages, while being closely related to the average and some of the quantiles seen.
   • Fashion
     • Fashion informs us about those that are repeated in more occasions. This measure is very useful in market research. when we measure an impression on a product with a likert scale