position measurements

position measurements

1. Position measures are values ​​that allow the data set to be divided into equal percentage parts and are used to classify an observation within a population or sample. The most common measures of position are quartiles, deciles, and percentiles.

2. Quantiles

   • Quartiles are the three values ​​of the variable that divide an ordered data set into four equal parts. % of the data. divide by 4 How are they calculated? Divide the set into four equal parts. For example, if the data set has 20 elements, N=20, we will have that the subject of the first quartile is (N+1)/4=(20+1)/4=21/4=5.25.

3. deciles

   • In descriptive statistics, a decile is any of the nine values ​​that divide an ordered data set into ten equal parts, each part representing 1/10 of the sample or population. How are they calculated? They are those variables that divide a distribution into 10 equal part, tsherefore there are 9 deciles. Decile 5 (D5) coincides with the median and with the second quartile, that is, D5= Me=Q2. The calculation of Deciles is similar to that of Quartiles and Percentiles.

4. Percentiles

   • The percentile is a measure of position used in statistics that indicates, once the data is ordered from smallest to largest, the value of the variable below which a given percentage of observations in a group is found. How is it solved? The percentile is a measure of non-central position. For example, if the set has 199 elements, (N+1) i/100=200 50/100=100, so the 50th percentile will be P50=X100.