Question

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Answer 1

The answer I have is 0.2235

Answer 2

>>The answer I have is 0.2235

Is this an answer you figured out or is it the correct answer you want to support?

Answer 3

And, are you studying binomial probability? @mickey4691

Answer 4

This does not require binomial probability.
This is what I did.
(7/17)^5 = 0.01184. I did this because I know exactly two has to be bushy, so I disregarded 7 lean trees.
Then, P(Tested) = 4/17.
therefore, p(Tested for exactly two bushy)= 4/17 - 0.01184 = 0.2235

Answer 5

@Directrix

Answer 6

I used binomial probability.

Prob of bushy = 10/17

Prob 0f lean = 7/17

Prob (2 Bushy and 2 Lean) = C(4,2) * (10/17) ² * (7/17) ² = .35 approx

http://www.wolframalpha.com/input/?i=C%284%2C2%29+*+%2810%2F17%29+%C2%B2+++*++%287%2F17%29+%C2%B2+%3D+

Answer 7

@kropot72 Please check this ^^^ when you are here again. Thanks.

Answer 8

Why did you suggest that the Prob (2 bushy and 2 Lean)?
There must be exactly 2 B, the other two can be BB, BL, LB or LL.

Answer 9

Four trees are to be randomly selected.

Of these 4, exactly 2 must be bushy which means the other 2 of the 4 must be lean.

Answer 10

If two is bushy, then the other two can be of any order, no?

Answer 11

The solution by @Directrix is correct. The question states "exactly 2 bushy trees", therefore the other two must be lean.

Answer 12

Is there an alternative approach from binomial probability?

Answer 13

Yes, I believe so. I need to think about it.