Hello,
I want to calculate 10 and 90th percentile of a signal. I want the function to find the closest corresponding time value (A:A) to the two threshold voltage values (B:B). I used the following to find the voltage threshold value (=.1*Max(B:B)) and (=.9*Max(B:B)) and need to find the corresponding time value. Using Lookup function , I was able to find the time value for the 10% percentile =Lookup(Voltage Threshold Value,B:B,A:A) but am not able to match the time value for the 90th percentile--the 90th percentile threshold value is 1.0009 and the closest matching number in the array is 1.012.

Any suggestions?