I could really use some help on this one, as I cannot remember what this kind of equation is called or how it can be done.

Here is the data I have inhand, which I am eventually trying to put into a chart in Excel.

best case worst case reproduce litters 5 10 sex ratio 2 3 females litter size 5 6 gestation period 19 21 days female life 2 3 years

female age to reproduce 4 weeks

So, step one was breaking the time down to days.

female life is 730 - 1095 days

female age to reproduce 28 days

By the "best / worst" at the top, I am trying to say the best case scenario (assuming we do not want a lot of mice), versus the worst case scenario.

The calculation is where I am having trouble. Once the female is 28 days old, it will give birth to 5 to 6 pups, 2 or 3 of which are female. The gestation period is 19 - 21 days, so nothing can be produced during this point of time. When the offspring are born, the system begins again, 2 or 3 of those females become 28 days old, then begin to reproduce in the same manner. Of course each female needs to stop reproducing at 730 - 1095 days...

I would not expect this to be viewable in one line, being that I gave a range of numbers, it would probably have to be two, but the calc should be the same.

If someone could please help me with figuring out this calculation, which I then need to move into Excel and graph, it would be most appreciated. Also, can you tell me what this calc is called? I know I have done this before, but it has been a long time.

Thank you so much,

Ryan