Selected Answer

Presume that

L = Lot (Reviewed quantity),

F = Faults found, and

Q = Quality level (Percentage of good products)

Now the formula you developed for calculating Q is as follows.

`Q = 1 - (F / L)`

Using simple rules for manipulating equations, you can determine the value of any third component of this formula if the two others are known. You learned this when first manipulating equations in - let me guess because I forgot - 7th grade. Remember? First resolve the parentheses:-

`1 - Q = F / L`

Therefore,

`(1 - Q)L = F`

and

`L = F / (1 - Q)`

and, for good measure,

`F = (1 - Q)L`