ONLINE 2
Question 1
If A and B are mutually exclusive events, with P(A) = 0.30 and P(B) = 0.40, then P(A υ B) is:
a.
0.1
c.
0.70.
b.
0.12.
d.
None of the above answers is co
ect.
Select one:
a. D
. C
c. A
d. B
Question 2
The table below shows the joint probabilities of events:
A1
A2
A3
B1
0.15
0.25
0.20
B2
0.10
0.15
0.15
The marginal probability for event A1 is:
a. 0.25
. 0.6
c. 0.35
d. 0.4
Select one:
a
c
d
Question 3
A discrete random variable can take either finite or infinite values as long as the values are countable.
Select one:
True
False
Question 4
If P(A) = 0.20, P(B) = 0.30 and P(A ∩ B) = 0.06, then A and B are:
a.
dependent events.
c.
mutually exclusive events.
b.
independent events.
d.
complementary events.
Select one:
a. D
. C
c. B
d. A
Question 5
If the event of interest is A, the probability that A will not occur is the complement of A.
Select one:
True
False
Question 6
Given a binomial random variable with n = 20 and p = 0.6, and using the binomial tables, the probability that P(X ≤ 13) is:
a. 0.126 b. 0.75
c. 0.874 d. 0.584
Select one:
a. C
. A
c. B
d. D
Question 7
The probability of event A and event B occu
ing must be equal to 1.
Select one:
True
False
Question 8
f X is a normal random variable with a mean of 78 and a standard deviation of 5, find
P( 70 ≤ X ≤ 77).
a XXXXXXXXXX XXXXXXXXXXb XXXXXXXXXX
c XXXXXXXXXX d XXXXXXXXXX
Select one:
B
A
D
C
Question 9
The concept of a sampling distribution
A. is essential for drawing conclusions about a population from the results of a sample
B. is related to the use of probability theory in inferential statistics
C. helps us to use statistics to estimate the co
esponding true values in the population.
D. All of the above
E. None of the above.
Select one:
B
A
E
D
C
Question 10
Gender is an example of a continuous random variable.
Select one:
True
False
Question 11
If P(A) = 0.10. and P(B given A) = 0.20, then P(A∩B) must be:
a. 0.4
. 0.02
c. 0,04
d. 0,01
Select one:
a
c
d
Question 12
Given a binomial random variable with n = 20 and p = 0.6, using the binomial table, find the probability that P(X ≤ 13).
a. 0.75 b. 0.126
c. 0.012 d. 0.25
Select one:
C
A
D
B
Question 13
Based on past exam results in principles of accounting you estimate that there is an 83% chance of passing the exam. This is an example of the subjective approach to probability.
Select one:
True
False
Question 14
The relative frequency approach to probability depends on the law of large numbers.
Select one:
True
False
Question 15
If n = 10, and p = 0.70, then the mean and standard deviation of a Binomial distribution are:
A. Mean = 7, standard deviation = 1.45
B. Mean = 0.07, standard deviation = 1.45
C. Mean = 1.45, standard deviation = 0.07
D. Mean = 1.45, standard deviation = 7
E. Mean = 7, standard deviation = 10
Select one:
A
B
C
D
E
Question 16
If A and B are mutually exclusive events with P(A) = 0.80, then P(B):
a.
Can take any value between 0 and 1.
b.
Can take any value between 0 and 0.80.
c.
Can be larger than 0.80.
d.
Cannot be larger than 0.20.
Select one:
a
c
d
Question 17
Let Z be the standard normal random variable. Find P(Z = 1).
A XXXXXXXXXX
B XXXXXXXXXX
C. 0
D XXXXXXXXXX
E XXXXXXXXXX
Select one:
A
B
C
D
E
Question 18
The collection of all possible outcomes of an experiment is called:
A.
a simple event.
B.
a sample space.
C.
a sample.
D.
a population.
Select one:
A
B
C
D
Question 19
An experiment consists of three stages. There are two possible outcomes in the first stage, three possible outcomes in the second stage, and four possible outcomes in the third stage. Drawing a tree diagram for this experiment will show that the total number of outcomes is:
a.
9.
c.
26.
b.
24.
d.
18.
Select one:
a. D
. C
c. A
d. B
Question 20
An experiment consists of three stages. There are two possible outcomes in the first stage, three possible outcomes in the second stage, and four possible outcomes in the third stage. Drawing a tree diagram for this experiment will show that the total number of outcomes is:
a.
9.
c.
26.
b.
24.
d.
18.
Select one:
a. D
. C
c. A
d. B
21)
Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.1949?
a.
0.51.
c.
0.86.
b.
–0.51.
d.
–0.86.
Select one:
a. A
. B
c. C
d. D
Online 3
Question1
The sample size needed to estimate a population mean to within 2 units with a 95% confidence when the population standard deviation equals 8 is:
a.
9.
c.
62.
b.
61.
d.
8.
Select one:
a.
. c
c. a
d. d
Question 2
The student's t distribution
A. assumes that the population data is normally distributed
B. assumes that the population standard deviation is unknown
C. approaches the Normal distribution when the sample size increases
D. generally has "fatter" tail areas than the Normal distribution
E. All of the above.
Select one:
a. E
. C
c. A
d. B
e. D
Question 3
,
the α/2 refers to:
a.
the probability that the confidence interval will contain the population mean.
b.
the probability that the confidence interval will not contain the population mean.
c.
the area in the lower tail or upper tail of the sampling distribution of the sample mean.
d.
the level of confidence.
Select one:
D
A
B
C
Question 4
A 90% confidence interval estimate of the population mean can be interpreted to mean that:
a.
if we repeatedly draw samples of the same size from the same population, 90% of the
values of the sample means will result in a confidence interval that includes the population
mean .
b.
there is a 90% probability that the population mean will lie between the lower confidence
limit (LCL) and the upper confidence limit (UCL).
c.
we are 90% confident that we have selected a sample whose range of values does not
contain the population mean .
d.
We are 90% confident that 10% the values of the sample means will result in a confidence
interval that includes the population mean .
Select one:
d
a
c
Question 5
A random sample of size, n = 11 was drawn and the sample standard deviation was clacuted to be 1.34. Use this information to construct a 99% confidence limits for σ2.
A. 0.820, 4.701
B. 0.727, 5.887
C. 0.876, 5.525
D. 0.713, 8.313
Select one:
A
C
D
B
Question 6
Which of the following best describes an interval estimator?a
A.
An interval estimator is the same as a point estimator.
B.
An interval estimator is an interval that draws inferences about a population based
on a sample statistic.
C.
An interval estimator can only be done for the population mean.
D.
An interval estimator can only be done for the population proportion.
Select one:
C
B
D
A
Question 7
A 90% confidence interval estimate for a population mean µ is determined to be 43.78 to XXXXXXXXXXIf the confidence level is increased to 95%, the confidence interval :
a.
becomes wider.
c.
becomes na
ower.
b.
remains the same.
d.
None of the above answers is co
ect.
Select one:
a
d
c
Question 8
The sample size needed to estimate a population mean to within 2 units with a 95% confidence when the population standard deviation equals 8 is:
a.
9.
c.
62.
b.
61.
d.
8.
Select one:
c
d
a
Question 9
In a criminal trial, a Type II e
or is made when:
a.
a guilty defendant is acquitted.
c.
a guilty defendant is convicted.
b.
an innocent person is convicted.
d.
an innocent person is acquitted.
Select one:
c
a
d
Question 10
The upper limit of a confidence interval at the 99% level of confidence for the population proportion if a sample of size 100 had 40 successes is:
a.
0.3040.
c.
0.4960.
b.
0.4047.
d.
0.4806.
Select one:
c
a
d
Question 11
Which of the following statement is true?
A. When estimating the population mean with an unknown population standard deviation, we use the student's t distribution.
B. The confidence interval for the mean will be na
ower for the 95% confidence level than for the 90% level.
C. The confidence interval for the mean will be wider for the 95% confidence level than for the 90% level.
D. Holding all other factors constant, when the standard deviation increases, the interval will be na
owe
E. Holding all other factors constant, decreasing the sample size will lead to a na
ower interval
Select one:
D
E
C
B
A
Question 12
A 95% confidence interval estimate for a population mean m is determined to be 43.78 to XXXXXXXXXXIf the confidence level is decreased to 90%, the confidence interval:
A.
becomes wider.
B.
remains the same.
C.
becomes na
ower.
D.
None of these choices are co
ect.
Select one:
D
C
B
A
Question 13
In a two-tail test for the population mean, if the null hypothesis is rejected when the alternative hypothesis is true:
a.
a Type I e
or is committed.
b.
a Type II e
or is committed.
c.
a co
ect decision is made.
d.
a one-tail test should be used instead of a two-tail test.
Select one:
d
a
c
Question 14
Which of the following statements is (are) not true?
a.
The probability of making a Type II e
or increases as the probability of making a
Type I e
or decreases.
b.
The probability of making a Type II e
or