SOLUTION: 13.Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sampl
Algebra ->
Probability-and-statistics
-> SOLUTION: 13.Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sampl
Log On
Question 1084781: 13.Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four students are absent?
You can put this solution on YOUR website! mean = 12 * 0.15 = 1.8
standard deviation is square root(12 * 0.15 * (1-0.15)) = 1.2369
:
P ( X = 4 ) = P ( X < or = 5 ) - P ( X < or = 4 )
:
z-score(5) = (5 - 1.8) / 1.2369 = 2.5871
z-score(4) = (4 - 1.8) / 1.2369 = 1.7786
:
look in table of z-values for associated probability
:
P ( X = 4 ) = 0.99516 - 0.96235 = 0.0328 approximately 0.03
:
