Answer
88
Work Step by Step
List the data from least to greatest: 65,67,77,79,81,83,88,89,91,95.
Percentile rank of a data value is the % of values that are less than or equal to that value.
Percentile rank of 70 means 70% of the grade is equal or less than the grade so the first 7 of the 10 data. So the grade is 88.