Question

Of the 232 airports available for public use in Themeliville, 121 are paved and lighted. For a simple random sample of 50, what is the probability that between 27 and 31 of the airports in the sample will be paved and lighted?

Answer 1

`39.17`

Explanation:

so we have the probability of being lighted as

`p(L) = 121/232`

this can be modeled using the binomial cumulative distribution thus

`p(27<=L<=31) = sum_(k=27)^31( ""_nC_k) p(L)^k (1-p(L))^(n-k)` where `n=50`

`p(27<=L<=31) =39.17`