Percentile of Ungrouped data

Given the following data: 2, 6, 6, 7, 8, 8, 9, 10, 10, 10, what is the 10th percentile using the Mendenhall Method?

If the 50th percentile is equal to 23.5, how many % of the data is equal and less than to 23.5?

If the 7th decile is equal to 56 how many % of the data is equal and less than to 56?

Given the following data: 2, 6, 6, 7, 8, 8, 9, 10, 10, 10, what is the 50th percentile using the Mendenhall Method?

If 25% of the data is equal to 30, then the ______ quartile is equal to 30.