Statistics help?

If P(A)=0.07692, P(B)=0.25, and Probability of A and B. =0.01923, what is Probability of A or B. to four decimal places? Select one.

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  • 4 weeks ago
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    To derive this equation, think of a deck of cards.

    how many cards are red or a king.

    There are 26 red cards and 4 kings.  total of 30.

    But there are two red kings which we just counted twice, so we have to subtract the "AND" count to get rid of the duplicates.  Total of 28.

    So the probability of (A or B) is:

    P(A or B) = P(A) + P(B) - P(A and B)

    We are given those values so substitute and simplify:

    P(A or B) = 0.07692 + 0.25 - 0.01923

    P(A or B) = 0.30769

    rounded to 4DP:

    P(A or B) = 0.3077

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