Statistics help. How to find probability?

[cruisx]

hey so i am trying to solve the following question but i have no idea how to solve it. I am confused by the %'sConsider a similar study done that shows that 96 % of those born in Canada can swim but only 83 % of new Canadians can swim. In a random group of 11 new Canadians, find the probability that at least 10 can swim.

The answer is 0.418933112054558

How is this answer obtained?
Now for at least, do i do p(10) + p(11), do i use a binomial formula or another one. I tried to do the mew = npq but that is not correct.

 

[mathman]

Use the binomial formula.

 

[cruisx]

THis one?

nCr p^r q^n-r

so

11C10 (0.83)^10 * (0.17)^1. Well its late, ill come back in the morning and try it again.

 

[HallsofIvy]

At least 10 means 10 or 11.

It is, as you said, p(10)+ p(11)=
_{11}C_{10}(.83)^{10}(.17)+ _{11}C_{11}(.83)^{11}= 11(.83)^{10}(.17)+ (.83)^{11}.