We are given the data set: 55,38,30,66,67,68,44 and wish to find the percentile for the data value 55.
(1) First we order the data set (either ascending or descending):
(2) A common approach to assigning a percentile is:
Percentile = `(("number of values below" X)+0.5)/("total number of values")*100%`
(There are many methods of assigning percentiles, quartiles, deciles, etc... You should check your text or notes to verify the procedure required.)
(3) For this example we have (P=Percentile):
`P=(3+0.5)/7*100%=50%` so 55 is at the `50^(th)` percentile.