Anonymous
Anonymous asked in Science & MathematicsMathematics · 10 months ago

Not sure what to do to show my work for this probability question?

Update:

In a recent survey, only 47% of Americans had a three-day supply of bottled water in case of emergency. Suppose a sample of 35 Americans is selected at random.

a. What is the probability that exactly 12 Americans have a three-day supply of bottled water on hand?

b. What is the probability that at least 18 Americans have a three-day supply of bottled water on hand?

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  • 10 months ago
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    Use the binomial probability formula.

    P(X = k) = C(n, k) * p^k * q^(n - k)

    n : number of trials (35)

    k : number of successes (12)

    p : probability of success (0.47)

    q : probability of failure (1-p = 0.53)

    Example:

    P(X = 12) = C(35, 12) * 0.47^12 * 0.53^23

    As for at least 18, you'd want to calculate the probability of 18 and above.

    P(X = 18) = 0.116755

    P(X > 18) = 0.243480

    P(X ≥ 18) = 0.360135

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