Neljänneksiin

Neljänneksiin is a Finnish term that translates to "quartiles" in English. In statistics, quartiles are values that divide a dataset into four equal parts. This means that one-quarter of the data points are less than or equal to the first quartile, half of the data points are less than or equal to the second quartile, and three-quarters of the data points are less than or equal to the third quartile.

The first quartile, often denoted as Q1, represents the 25th percentile of the data. The second quartile, Q2, is the median of the dataset and corresponds to the 50th percentile. The third quartile, Q3, represents the 75th percentile. These values are useful for understanding the spread and distribution of data.

Calculating quartiles involves first ordering the data from smallest to largest. If the number of data points is odd, the median is the middle value. If the number of data points is even, the median is the average of the two middle values. Q1 is the median of the lower half of the data (excluding the median if the total number of data points is odd), and Q3 is the median of the upper half of the data (again, excluding the median if the total number of data points is odd).

The interquartile range (IQR), calculated as Q3 - Q1, is a measure of statistical dispersion. It represents the range of the middle 50% of the data and is less sensitive to outliers than the overall range of the dataset. Neljänneksiin are fundamental tools in descriptive statistics for summarizing and analyzing data.