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grr i cant get this!!!?

An investor owns three common stocks. Each stock, independent of the others, has equally likely chances of (1) increasing in value, (2) decreasing in value, or (3) remaining the same value. Estimate the probability at least two of the stocks increase in value.

Estimate the probability at least two of the stocks increase in value.___

ive been working on this for a long time

2 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    Just draw a tree diagram :)

    Okay, so we know each individual chance is 1/3. How many combinations can work?

    112

    113

    121

    131

    211

    311

    Each one is worth 1/27 probability. 6 of them gives us 6/27 chance that at least 2 stocks will increase in value :)

  • 1 decade ago

    At least two...

    P(s1s2)+P(s1s3)+P(s2s3) + P(s1s2s3) = (1/3)*(1/3)*3 + (1/3)*(1/3)*(1/3) = 1/3 + 1/27 = 10/27

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