To find roots in a loop

Dear All,

i'm trying to get the range of ovality value wrt to a range of external pressure, using Murphey Langner equation.

I've tried it using a simple root fuction in mathcad in a loop but it doesnt work.

appreciate your assistant to guide me what did i went wrong and how to resolve it

thank you...

my extracted spreadsheet is as follows

Regards

-Akmal-