posted by Sherri on .
If the probability of a swan drowning is 0.23, find the probability of exactly 4 out of the 7 swans drowning.
I think that the answer is:
is the right?
*round your answer to 3 significant digits*
p of drowning = .23
1-p = prob of not drowning = .77
In general the probability of k hits in n trials is
C(n,k) p^k (1-p)^(n-k)
(binomial random variable )
so here we want
C(7,4)* .23^4 * .77^3
C(7,4) from Pascal's triangle of combination formula = 35
35 * .23^4 * .77^3 = .0447
thank you so much!!!
If the probability of a lame leaping lord is 0.24