BUSA 3321 Practice Exam 3
Let X be a binomial random variable with n=20 and p=.30. Use the binomial table
to find P [X=2].
a. .027*
b. .004
c. .023
d. none of the above
Let X be a binomial random variable with n=20 and p=.30. The expected value
(mean) of X is
a. 4
b. 5
c. 6*
d. none of the above
Let X be a binomial random variable with n=20 and p=.30. The variance of X is
a. 25
b. 35
c. 4.2
d. none of the above
. Which of the following is not necessary for a binomial random variable X
a. N trials
b. Probability p of success on each trial
c. Independence from trial to trial
d. Mutually exclusive outcomes from one trial to the next trial*
Suppose a jury panel of several thousand persons has 50% women. What is the
probability that a jury of 6 persons will have exactly 3 women and 3 men?
a. .344
b. .656
c. .312*
d. none of the above
Suppose a jury panel of several thousand persons has 50% women. What is the
probability that a jury of 6 persons will have at least one woman? Choose the
answer correct to two decimal places.
a. .984*
b. .016
c. .50
d. none of the above
Given that the random variable X is normally distributed with a mean of 80 and a
standard deviation of 10, P[85<X<90] is
a. .5328
b. .3413
c. .1915
d. .1498*
If the z-value for a given value x of the random variable X is z=1.96, and the
distribution of X is normal with a mean of 60 and a standard deviation of 6, to
what x-value does this z-value correspond?
a. 71.76*
Let X be a binomial random variable with n=20 and p=.30. Use the binomial table
to find P [X=2].
a. .027*
b. .004
c. .023
d. none of the above
Let X be a binomial random variable with n=20 and p=.30. The expected value
(mean) of X is
a. 4
b. 5
c. 6*
d. none of the above
Let X be a binomial random variable with n=20 and p=.30. The variance of X is
a. 25
b. 35
c. 4.2
d. none of the above
. Which of the following is not necessary for a binomial random variable X
a. N trials
b. Probability p of success on each trial
c. Independence from trial to trial
d. Mutually exclusive outcomes from one trial to the next trial*
Suppose a jury panel of several thousand persons has 50% women. What is the
probability that a jury of 6 persons will have exactly 3 women and 3 men?
a. .344
b. .656
c. .312*
d. none of the above
Suppose a jury panel of several thousand persons has 50% women. What is the
probability that a jury of 6 persons will have at least one woman? Choose the
answer correct to two decimal places.
a. .984*
b. .016
c. .50
d. none of the above
Given that the random variable X is normally distributed with a mean of 80 and a
standard deviation of 10, P[85<X<90] is
a. .5328
b. .3413
c. .1915
d. .1498*
If the z-value for a given value x of the random variable X is z=1.96, and the
distribution of X is normal with a mean of 60 and a standard deviation of 6, to
what x-value does this z-value correspond?
a. 71.76*
