With the data arranged in ascending order (−40.33%, −5.02%, 9.57%, 10.02%, 12.34%, 15.25%, 16.54%, 20.65%, 27.37%, and 30.79%), the 8.8th position would be between the 8th and 9th entries, 20.65% and 27.37%, respectively. How to find value in the 8.8th position using linear interpolation using ba ii plus?
I really appreciate the help!
Check the calculator tip section for how to perform linear interpolation with the BAII!!! 
a thousand thank you!