Excel: How to make cell blank if formula returns an error or a number less than 0 or greater than 1?

I am working on an Excel spreadsheet and want to make my formulas return a blank cell if the formula returns an error, a number less than 0, or a number greater than 1. I cannot get my head wrapped around how to construct this IF statement. Here is my current formula:

P9=IF(AVERAGE(C9:O9)<0.001,"",AVERAGE(C9:O9)-1)/4

Q9=IF(B9<1,"",(B9-1)*P9/4)