First Quartile And Third Quartile Meaning. There are many measurements of the variability of a set of data. Similar to how the median denotes the midway point of a data set the first quartile marks the quarter or 25 point.
If the number of data points is a multiple of 4 there is a largest number in the lowest quarter and a smallest number in the highest three quarters. The third quartile can be measured as the middle value between the median and highest values of the data set. This means that about 25 of the numbers in the data set lie below Q 1 and about 75 lie above Q 1.
Splits off the lowest 25 of data from the highest 75 The second middle quartile or median of a data set is equal to the 50th percentile of the data cuts data in half The third quartile called upper quartile QU is equal to the 75th percentile of the data.
The first quartile is a quarter of the way through. The formula for this is. Jul 26 2010 The first quartile denoted by Q 1 is the median of the lower half of the data set. With an input of 0 quartile returns the minimum.
