The approximate percent increase in the average grade is 21.43%.
Percentage is a measure of frequency that expresses a number as a value out of hundred. The sign used to denote percentage is%.
Percentage increase = (new grade / initial grade) - 1
(85 / 70) - 1 = 0.2143 = 21.43%
To learn more about percentages, please check: https://brainly.com/question/25764815
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