The following are weights (in pounds) for a sample of 11 baby girls at the age of 10 months:
17.2 18.4 18.8 20.3 20.6 21.1 22 23.5 24.6 25.4 26.8
The 80th percentile for these sample data is pounds. In the sample data, out of 11 observations are less than or equal to the 80th percentile, and out of 11 observations are greater than or equal to this value. For any data set, the first quartile is the percentile, the second quartile is the percentile and the third quartile is the percentile. The first quartile for the prior sample data is pounds.