In your code, where you have
"Percent X"*100
the text inside the quotes is a character string which cannot be used in arithmetic.
You may want
percent_x=percent_x*100;
note that percent_x is a variable name, it is not in quotes, and it contains an underscore instead of a space as you originally wrote it, but this method does not append a % character after the number ... so ...
probably better is to leave the value unchanged, do not perform the above step, and instead apply the PERCENTw.d format to the variable percent_x, for example
format percent_x percent8.2;
which makes the value of the variable appear as if it had been multiplied by 100 and appends a % character after the number.
--
Paige Miller