Sort the data from smallest to largest
Count the total number of values
Find the percentile position using the formula: position = (percentile / 100) × (n + 1)
If the position is a whole number, take the value at that position
If the position is not a whole number, interpolate between the two surrounding values
For grouped or large datasets, use the cumulative frequency to locate the percentile class
Identify the value below which the given percentage of data falls
Repeat the process for any percentile you need to find