Injector pulse width calculation

For a theoretical calculation, why the injector pulse width is = cycle time x injector duty cycle? Why we need the cycle time to inject the necessary fuel in one cycle? We only need the time that the injector should inject the to achive the mass of gasoline necessary for that specific afr

Duty Cycle is the percentage of the cycle time -- so you need to know the time, so you can multiply by the percentage to get the injector open time.

More easy to understand to me like this: if i need 0,000154lbs of fuel per intake cycle (what is equal to 0,462lbs in 1 minute at 6000rpm), and my injector suply 1lb per 60 seconds, then is equal to 0,000154lbs x 60= 0.00924 seconds. 9,24 ms.