First, arrange the data from lowest to highest
19, 20, 21, 22, 23, 24, 25, 27, 29, 30, 33
Next, find the media or the middle data.
The median is 24.
19, 20, 21, 22, 23, 24 (median), 25, 27, 29, 30, 33
Lastly, look at the data below the median and find the middle of those data. If it's between two numbers, choose the lower number. That's the first quartile.
The first quartile is 21.
19, 20, 21(Q1), 22, 23, 24 (median), 25, 27, 29, 30, 33
