Excel formula quick help URGENT

Urgently need help to understand an Excel formula (found online) so I can applied it to my own data. Here is the formula and I will provide the data to the person who takes the job.
I need just a description in simple words of every step of the calculations used in this formula.
Due: ASAP (Monday morning before 7am U.S. Pacific Time)
Please reply and I will send you the excel file so you can also look at the formula in it - as it is applied. Here is the formula:

=IF(IF(D15>$C$4=TRUE,1-I15/GETPIVOTDATA(" CPA",$A$13),"Not Statistically Significant")="Not Statistically Significant",IF(D15>$C$4=TRUE,1-I15/GETPIVOTDATA(" CPA",$A$13),"Not Statistically Significant"),IF(IF(D15>$C$4=TRUE,1-I15/GETPIVOTDATA(" CPA",$A$13),"Not Statistically Significant")>900%,900%,IF(IF(D15>$C$4=TRUE,1-I15/GETPIVOTDATA(" CPA",$A$13),"Not Statistically Significant")$C$4=TRUE,1-I15/GETPIVOTDATA(" CPA",$A$13),"Not Statistically Significant"))))