kwartylami

Kwartylami is a Polish term that translates to "quartiles" in English. Quartiles are values that divide a dataset into four equal parts. They are a type of quantile, which are points taken at regular intervals from the cumulative distribution function of a random variable. The three quartiles are denoted as Q1, Q2, and Q3.

Q1, the first quartile, is the value below which 25% of the data falls. It is also known as the lower quartile. Q2, the second quartile, is the median of the dataset, meaning 50% of the data falls below this value. Q3, the third quartile, is the value below which 75% of the data falls. It is also known as the upper quartile.

To calculate quartiles, the data must first be ordered from smallest to largest. If the number of data points is odd, the median is the middle value. For an even number of data points, the median is the average of the two middle values. The first quartile (Q1) is the median of the lower half of the data (excluding the median if the total number of data points is odd). The third quartile (Q3) is the median of the upper half of the data (excluding the median if the total number of data points is odd).

Quartiles are useful for understanding the spread and distribution of data. The interquartile range (IQR), calculated as Q3 - Q1, represents the range of the middle 50% of the data and is a measure of statistical dispersion. Quartiles are often used in descriptive statistics, data visualization (e.g., in box plots), and for identifying outliers.