steering ratio and c-factor selection

[mohab]

now I select total steering ratio 3:1

now I need to select steering rack c-factor

the eq from R.C.V.D
steering ratio = sin-1(c-factor/steering arm length)/360

if steering ratio = 3
steering arm length = 6 cm
then c- factor = not logic numbers

if c-factor =1 is that mean rack will travel 1 in for 1 rotation of pinion ???
please I need your help thank you