A percentile for ungrouped data is a value that divides the data into 100 equal parts. For example, the 50th percentile is the median of the data, which means that 50% of the data values are below or equal to it. To find a percentile for ungrouped data, we can use the formula: P = L + (n/100) * i where P is the percentile value, L is the lower limit of the class interval containing the percentile, n is the cumulative frequency of the class interval containing the percentile, and i is the width of the class interval.