Average Annual Salary of a Cosmetologist. As of 2008 the median salary for a cosmetologist in the United States was $11.13, which includes tips and commission. The lower 10th percentile earned on average $7.47 hourly, while the upper 90th percentile earned a median salary of $20.41 hourly.verage Annual Salary of a Cosmetologist. As of 2008 the median salary for a cosmetologist in the United States was $11.13, which includes tips and commission. The lower 10th percentile earned on average $7.47 hourly, while the upper 90th percentile earned a median salary of $20.41 hourly.
The median is the ((n + 1)/2)th item, where n is the number of values. For example, for the list {1, 2, 5, 7, 8}, we have n = 5, so the median is the ((5 + 1)/2)th item.
Median is the middle data value of an ordered data set. 1  If there are two middle values, then the median is the mean of the two numbers. The middle numbers from the above data set are 30 and 31. 2  As there are two middle numbers we have to find the mean of those numbers. = = 3  30.5. 4  So, 30.5 is the median (middle value) of the data set 33, 30, 42, 22, 18, and 31.