CHAPTER FOUR
Probability
1. State whether the following question provided is qualitative or quantitative data and
indicate the measurement scale
... [Show More] appropriate -Are you a male or female?
a. Qualitative, ratio
b. Quantitative, ratio
c. Qualitative, nominal
d. Quantitative, ordinal
2. State whether the following question provided is qualitative or quantitative data and
indicate the measurement scale appropriate - How long have you been in your present
job or position
a. Qualitative, ratio
b. Quantitative, ratio
c. Qualitative, nominal
d. Quantitative, ordinal
• 2. State whether the following question provided is qualitative or quantitative data
and indicates the measurement scale appropriate - What is your age?
– Qualitative, ratio
– Quantitative, ratio
– Qualitative, nominal
– Quantitative, ordinal
The Wall Street Journal subscriber survey (October 13, 2013) asked 46 questions about
subscriber characteristics and interest. State whether each of the following questions
provided qualitative or quantitative data and indicate the measurement scale appropriate for
each.
a) What is your age?
b) Are you male or female?
c) When did you first start reading the WSJ? High school, college, early career, midcareer,
late career, or retirement?
d) How long have you been in your present job or position?
e) What type of vehicle are you considering for your next purchase? Nine response
categories include sedan, sports car, SUV, minivan, and so on.
Ans a). Age: Quantitative; ratio scale of measurement
b). Gender: Qualitative; nominal scale of measurement
c). When start reading WSJ? Qualitative; ordinal scale of measurement
since the responses can be ordered from earliest (high school) to latest (retirement)
d). How long in job? Quantitative; ratio scale of measurement
e). Type of vehicle: Qualitative; nominal scale of measurement
12. When outliers are present in the data set, the ________ is the best choice to measure
central tendency.
A) median B) standard deviation C) mean D) mode
E) none of the above
3. What is the median of the following set of numbers? {12,8,13,4,7,6,3,3,15}
a) 12 b) 8 c) 7 d) 7.5
4. The hourly wages of a sample of 130 system analysts are given below.
mean = 60 range = 20
mode = 73 variance = 324
median = 74
The coefficient of variation equals
a. 0.30%
b. 30%
c. 5.4%
d. 54%
5. The variance of a sample of 169 observations equals 576. The standard deviation of the
sample equals
a. 13
b. 24
c. 576
d. 28,461
6. The median of a sample will always equal the
a. mode
b. mean
c. 50th percentile
d. all of the above answers are correct
7. A sample selected in such a manner that each sample of size n has the same probability of
being selected is
a. a convenience sample
b. a judgment sample
c. nonprobabilistic sampling
d. a simple random sample
8. Which of the following sampling methods is a probabilistic sampling method?
a. judgment sampling
b. convenience sampling
c. cluster sampling
d. None of these alternatives is correct.
9. An uncertain future event affecting the consequence, or payoff, associated with a decision is
known as
a. unconditional probability
b. unknown probability
c. chance event
d. uncertain probability
10. Nodes indicating points where a decision is made are known as
a. decision nodes
b. chance nodes
c. marginal nodes
d. conditional nodes
11. In computing an expected value (EV), the weights are
a. decision alternative probabilities
b. in pounds or some unit of weight
c. in dollars or some units of currency
d. the state-of-nature probabilities
12. Below you are given a payoff table involving three states of nature and two decision
alternatives.
Decision
Alternative
States of Nature
S1 S2 S3
A 80 45 -20
B 40 50 15
The probability that S1 will occur is 0.1; the probability that S2 will occur is 0.6. The
recommended decision based on the expected value criterion is
a. A
b. B
c. Both alternatives are the same.
d. None of these alternatives is correct.
13. The degrees of freedom for a contingency table with 6 rows and 3 columns is
a. 18
b. 15
c. 6
d. 10
14. If the coefficient of determination is a positive value, then the coefficient of correlation
a. must also be positive
b. must be zero
c. can be either negative or positive
d. must be larger than 1
15. Regression analysis is a statistical procedure for developing a mathematical equation that
describes how
a. one independent and one or more dependent variables are related
b. several independent and several dependent variables are related
c. one dependent and one or more independent variables are related
d. None of these alternatives is correct.
16. Given below are five observations collected in a regression study on two variables x
(independent variable) and y (dependent variable). Develop the least squares estimated
regression equation
x y
10 7
20 5
30 4
40 2
50 1
a. Y = 8.3-0.15x
b. Y= 9+0.15x
c. Y= 8.3+0.15x
d. 9-0.15x
17. As the sample size increases, the margin of error
a. increases
b. decreases
c. stays the same
d. increases or decreases depending on the size of the mean
18. In computing the standard error of the mean, the finite population correction factor is used
when
a. N/n > 0.05
b. N/n 0.05
c. n/N > 0.05
d. n/N 30
19. Z is a standard normal random variable. What is the value of Z if the area to the right of Z is
0.9803?
a. -2.06
b. 0.4803
c. 0.0997
d. 3.06
20. For a standard normal distribution, the probability of obtaining a z value between -2.4 to -2.0
is
a. 0.4000
b. 0.0146
c. 0.0400
d. 0.5000
21. For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is
a. 0.1600
b. 0.0160
c. 0.0016
d. 0.9452
22. The number of electrical outages in a city varies from day to day. Assume that the number of
electrical outages (x) in the city has the following probability distribution.
x f(x)
0 0.80
1 0.15
2 0.04
3 0.01
The mean and the standard deviation for the number of electrical outages (respectively) are
a. 2.6 and 5.77
b. 0.26 and 0.577
c. 3 and 0.01
d. 0 and 0.8
23. Assume that you have a binomial experiment with p = 0.4 and a sample size of 50. The
variance of this distribution is
a. 20
b. 12
c. 3.46
d. 144
24. In a binomial experiment the probability of success is 0.06. What is the probability of two
successes in seven trials?
a. 0.0036
b. 0.0600
c. 0.0555
d. 0.2800
25. If P(A) = 0.62, P(B) = 0.47, and P(A B) = 0.88, then P(A U B) =
a. 0.2914
b. 1.9700
c. 0.6700
d. 0.2100
1. What type of variable is each of the following?
1. hair colour
2. number of television sets in a private home
3. possible responses to questionnaire items are: yes, no, don't know
4. earthquake intensity
5. final position in a race - 1st, 30th, etc.
1. Ans hair colour: Qualitative, Nominal
2. number of television sets in a private home: Quantitative, Discrete
3. possible responses to questionnaire items are: yes, no, don't know: Qualitative,
Nominal
4. earthquake intensity: Quantitative, Continuous
5. final position in a race - 1st, 30th, etc.: Qualitative, Ordinal
101
D 1. Which of the following is not a method of assigning [Show Less]