Conditional Probability

[dusty chasm]

please could someone explain how to do part C? i did part A with binomial

[inland bear]

1. Wait patiently for a helper to come along.
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[rare bolt]

That's incorrect. In (a) you need to use hypergeometric distribution. After all, the probability of picking a female puppy changes each time you take a puppy out.

[dusty chasm]

i forgot, yea

5/9 x 4/8 x 3/7 x 5/6 x 4

[dusty chasm]

why is it x 4?

[rare bolt]

No, that's incorrect. Let's use the general formula.
We have X ~ HG(N = 9, D = 5, n = 4). For a hypergeometric rand variable:
P(X = k) = C(D, k)C(N - D, n - k)/C(N, n)
So, in our case:
P(X = 3) = C(5, 3)C(4, 1)/C(9, 4)
Now you just need to calculate it.

[dusty chasm]

thank you

+close