fgcu

posted by .

More than a decade ago, high levels of lead in the blood put 88% of children at risk. A concerted effort was made to remove lead from the environment. Now, suppose only 12% of children in the United States are at risk of high blood-lead levels.

(a) In a random sample of 194 children taken more than a decade ago, what is the probability that 50 or more had high blood-lead levels? (Round your answer to three decimal places.)

  • Stats -

    n=194
    P(r >/= 50)
    p= .12 (converted percent to decimal)
    q= 1-p = 1-.12 = .88
    P(x) = r-.5 if r is to the left(greater than) therefore,

    P(x>/= 49.5)

    You need P(z>/= ?)

    So:
    mean (mu) = np = (194)(.12) = 23.28

    stan. dev. (sigma) = sqrt(npq) = (194)(.12)(.88) = 4.526

    z= (x - mu)/sigma = (49.5 - 23.28)/4.526 = 5.79

    So: P(z >/= 5.79), now you look up the probability on your z-chart and there's your answer.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    Lead Contamination More than a decade ago high levels of lead in the blood put 88% of children at risk. A concerted effort was made to remove lead from the environment. In a random sample of 200 children taken more than a decade ago, …
  2. English

    1. We will lead your children to the joys of reading. 2. We will lead your children to the joy of reading. 3. We will lead your children to joy of reading. (Which expressions are grammatical?
  3. public health

    what does it means to have high levels of lead in your blood
  4. Statistics

    Suppose that more than a decade ago high levels of lead in the blood put 81 percent of children at risk. A concerted effort was made to remove lead from the environment. Suppose, according to a survey, only 5 percent of children in …
  5. Public Health

    All of the following are true of lead as an environmental hazard except?
  6. statistics

    In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. More than a decade ago, high levels of lead in the blood …
  7. Teaching in Early childhood progras

    Why should teachers offer a variety of small-group activities for children every day?
  8. Statistic

    In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. More than a decade ago, high levels of lead in the blood …
  9. Statistics

    In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. More than a decade ago, high levels of lead in the blood …
  10. Supportive learning environment

    Which of the following statements is true regarding children living in poverty?

More Similar Questions