Q3 refers to the third quartile, which is a statistical measure used in data analysis and represents the value below which 75% of the data points fall. The formula for calculating Q3 depends on the method used to determine quartiles.
If you have a dataset with n data points and you are using the method known as the "Tukey method" or "Hinges method," the formula for calculating Q3 is:
Q3 = L + (0.75 * IQR)
where L is the lower quartile (Q1) and IQR is the interquartile range. The interquartile range is the difference between the upper quartile (Q3) and the lower quartile (Q1).
Alternatively, some other methods may use slightly different formulas or definitions for quartiles. For example, the "Median-Position" method considers the median (Q2) and calculates Q3 as the median of the upper half of the data.
It's important to note that the specific formula used for Q3 may vary depending on the statistical software or method you are using. The formulas mentioned above are commonly used, but it's always a good practice to consult the documentation or guidelines of the specific statistical method or software you are working with to ensure accuracy.