Forty-five percent of households say they would feel secure if they had​ $50,000 in savings. You randomly select 8 households and ask them

Question

Forty-five percent of households say they would feel secure if they had​ $50,000 in savings. You randomly select 8 households and ask them if they would feel secure if they had​ $50,000 in savings. Find the probability that the number that say they would feel secure is​ (a) exactly​ five, (b) more than​ five, and​ (c) at most five.

in progress 0
Khang Minh 5 months 2021-08-09T20:20:02+00:00 1 Answers 7 views 0

Answers ( )

    0
    2021-08-09T20:21:12+00:00

    Answer:

    0.172 ; 0.0884 ; 0.9115

    Step-by-step explanation:

    Proportion or those who feel secure, p = 0.45

    Sample size, n = 8

    Using the binomial distribution formula :

    P(x =x) = nCx * p^x * (1 – p)^(n – x)

    A.) p(x = 5)

    P(x =5) = 8C5 * 0.45^5 * 0.55^3

    P(x = 5) = 56 * 0.0184528125 * 0.166375

    P(x = 5) = 0.1719248540625

    P(x = 5) = 0.172

    B.) P(x > 5)

    P(x > 5) = P(x = 6) + P(x = 7) + P(x = 8)

    P(x > 5) = 0.0703 + 0.0164 + 0.0017

    P(x > 5) = 0.0884

    C.) P( ≤ 5) = P(x = 0) + P(x = 1) + P(x = 2) + P(x = 3) + P(x = 4) + P(x = 5)

    Using the binomial probability calculator to obtain a direct solution :

    P( ≤ 5) = 0.9115

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )