Tricky Question

Hi,
I have this qn that dosent seem to give me enough info to work it out (though I suppose it does and I just cant do it)

-94,075 babies born over a period of time. Then were diagnosed as achondroplastic dwarfs, an autosomal dominant trait showing full penetrance. Only two dwarfs had a dwarf parent. What is the mutation frequency in the gametes? Assume all mutations occured in the gametes.

Im not sure what to do.
Thanks for any help

I think there is a type-o in this question. It probably should say ten not then: "Ten were diagnosed as achondroplastic dwarfs". If so, then 10-2=8 (exclude those with dwarf parents) => 8 out of 94,075 are mutation products. With 2 parents per baby there are 94,075x2=188,150 gametes and since it is a dominant trait only 8 gametes were mutant. Thus, 8/188,150= 0.0000425 is the frequency of the mutation.

Oh yeah. Thanks, I probably should have thought of that! Thanks for your help