Download Practice Test 1 –Bus 2023 Directions: For each question find the

Practice Test 1 –Bus 2023
Directions: For each question find the answer that is the best solution provided. There is only one
correct answer.
1.
Facts and figures that are collected, analyzed and summarized for presentation and
interpretation are
a.
data
b.
variables
c.
elements
d.
Both variables and elements are correct.
2.
All the data collected in a particular study are referred to as the
a.
census
b.
inference
c.
variable
d.
data set
3.
Quantitative data
a.
are always nonnumeric
b.
may be either numeric or nonnumeric
c.
are always numeric
d.
are always labels
4.
Qualitative data
a.
are always nonnumeric
b.
may be either numeric or nonnumeric
c.
are always numeric
d.
indicate either how much or how many
5.
Arithmetic operations are inappropriate for
a.
qualitative data
b.
quantitative data
c.
both qualitative and quantitative data
d.
large data sets
6.
In a questionnaire, respondents are asked to record their age in years. Age is an example of a
a.
qualitative variable
b.
quantitative variable
c.
qualitative or quantitative variable, depending on how the respondents answered the
question
d.
ratio variable
7.
In an application for a credit card, potential customers are asked for their social security numbers.
A social security number is an example of a
a.
qualitative variable
b.
quantitative variable
c.
qualitative or quantitative variable, depending on how the respondents answered the
question
d.
ratio variable
1
8.
Data collected at the same, or approximately the same, point in time are
a.
time series data
b.
approximate time series data
c.
cross-sectional data
d.
approximate data
9.
Data collected over several time periods are
a.
time series data
b.
time controlled data
c.
cross-sectional data
d.
time cross-sectional data
10.
Statistical studies in which researchers do not control variables of interest are
a.
experimental studies
b.
uncontrolled experimental studies
c.
not of any value
d.
observational studies
11.
Statistical studies in which researchers control variables of interest are
a.
experimental studies
b.
control observational studies
c.
non experimental studies
d.
observational studies
12.
A frequency distribution is
a.
a tabular summary of a set of data showing the fraction of items in each of several
nonoverlapping classes
b.
a graphical form of representing data
c.
a tabular summary of a set of data showing the number of items in each of several
nonoverlapping classes
d.
a graphical device for presenting qualitative data
13.
The sum of frequencies for all classes will always equal
a.
1
b.
the number of elements in a data set
c.
the number of classes
d.
a value between 0 and 1
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours
0- 9
10 - 19
20 - 29
30 - 39
Frequency
20
80
200
100
2
14.
Refer to Exhibit 2-1. The class width for this distribution
a.
is 9
b.
is 10
c.
is 39, which is: the largest value minus the smallest value or 39 - 0 = 39
d.
varies from class to class
15.
Refer to Exhibit 2-1. The midpoint of the last class is
a.
50
b.
34
c.
35
d.
34.5
16.
Refer to Exhibit 2-1. The number of students working 19 hours or less
a.
is 80
b.
is 100
c.
is 180
d.
is 300
17.
Refer to Exhibit 2-1. The relative frequency of students working 9 hours or less
a.
b.
c.
d.
18.
is 20
is 100
is 0.95
0.05
Refer to Exhibit 2-1. The cumulative relative frequency for the class of 20 - 29
a.
b.
c.
d.
is 300
is 0.25
is 0.75
is 0.5
19.
A graphical device for presenting qualitative data summaries based on subdivision of a circle into
sectors that correspond to the relative frequency for each class is a
a.
histogram
b.
stem-and-leaf display
c.
pie chart
d.
bar graph
20.
Qualitative data can be graphically represented by using a(n)
a.
histogram
b.
frequency polygon
c.
ogive
d.
bar graph
21.
The mean of a sample is
a.
always equal to the mean of the population
b.
always smaller than the mean of the population
c.
computed by summing the data values and dividing the sum by (n - 1)
d.
computed by summing all the data values and dividing the sum by the number of items
3
22.
After the data has been arranged from smallest value to largest value, the value in the middle is
called the
a.
range
b.
median
c.
mean
d.
None of the other answers are correct.
23.
The 75th percentile is also the
a.
first quartile
b.
second quartile
c.
third quartile
d.
fourth quartile
24.
Which of the following is NOT a measure of location?
a.
mean
b.
median
c.
variance
d.
mode
25.
is the
The measure of location that is the most likely to be influenced by extreme values in the data set
a.
b.
c.
d.
range
median
mode
mean
26.
The difference between the largest and the smallest data values is the
a.
variance
b.
interquartile range
c.
range
d.
coefficient of variation
27.
The variance of the sample
a.
can never be negative
b.
can be negative
c.
cannot be zero
d.
cannot be less than one
28.
The variance of a sample of 81 observations equals 64. The standard deviation of the sample
equals
a.
0
b.
4096
c.
8
d.
6,561
29.
Which of the following symbols represents the size of the sample
a.
2
b.

c.
N
d.
n
4
30.
Which of the following symbols represents the mean of the sample?
a.
2
b.

c.

x
d.
Exhibit 3-2
A researcher has collected the following sample data. The mean of the sample is 5.
3
5
12
3
2
31.
Refer to Exhibit 3-2. The variance is
a.
80
b.
4.062
c.
13.2
d.
16.5
32.
Refer to Exhibit 3-2. The standard deviation is
a.
8.944
b.
4.062
c.
13.2
d.
16.5
33.
For any continuous random variable, the probability that the random variable takes on exactly a
specific value is
a.
1.00
b.
0.50
c.
any value between 0 to 1
d.
zero
34.
The highest point of a normal curve occurs at
a.
one standard deviation to the right of the mean
b.
two standard deviations to the right of the mean
c.
approximately three standard deviations to the right of the mean
d.
the mean
35.
A standard normal distribution is a normal distribution with
a.
a mean of 1 and a standard deviation of 0
b.
a mean of 0 and a standard deviation of 1
c.
any mean and a standard deviation of 1
d.
any mean and any standard deviation
36.
Z is a standard normal random variable. The P(1.20  z  1.85) equals
a.
0.4678
b.
0.3849
c.
0.8527
d.
0.0829
5
37.
Z is a standard normal random variable. The P(1.05 < z < 2.13) equals
a.
0.8365
b.
0.1303
c.
0.4834
d.
None of the alternative answers is correct.
38.
A numerical measure of linear association between two variables is the
a.
variance
b.
covariance
c.
standard deviation
d.
coefficient of variation
39.
Positive values of covariance indicate
a.
a positive variance of the x values
b.
a positive variance of the y values
c.
the standard deviation is positive
d.
a positive relation between the x and the y variables
40.
Positive values of covariance indicate
a.
a positive variance of the x values
b.
a positive variance of the y values
c.
the standard deviation is positive
d.
a positive relation between the x and the y variables
41. In regression analysis, the variable that is being predicted is the
a.
dependent variable
b.
independent variable
c.
intervening variable
d.
None of these answers is correct.
42. Regression analysis was applied between sales (in $1,000) and advertising (in $100), and the
following regression function was obtained.
 = 80 + 6.2 x
Y
Based on the above estimated regression line, if advertising is $10,000, then the point estimate for
sales (in dollars) is
a.
$62,080
b.
$142,000
c.
$700
d.
$700,000
43.If the coefficient of correlation is 0.8, the percentage of variation in the dependent variable explained
by the estimated regression equation is
a.
0.80%
b.
80%
c.
0.64%
d.
64%
6
44. If the coefficient of determination is equal to 1, then the coefficient of correlation
a.
must also be equal to 1
b.
can be either -1 or +1
c.
can be any value between -1 to +1
d.
must be -1
7
Short Answer: Answer all of the following questions. Make sure to show all work. Solutions
with no work will receive no credit.
1.You are given the following data on the price/earnings (P/E) ratios for twelve companies.
Construct a stem-and-leaf display. Specify the leaf unit for the display.
23
8
25
36
39
48
47
28
22
37
37
26
8
2. The grades of 10 students on their first management test are shown below.
94
68
a.
b.
c.
61
75
96
85
66
84
92
78
Construct a frequency distribution. Let the first class be 60 - 69.
Construct a cumulative frequency distribution.
Construct a relative frequency distribution.
9
3. The hourly wages of a sample of eight individuals is given below.
Individual
Hourly Wage (dollars)
A
B
C
D
E
F
G
H
27
25
20
10
12
14
17
19
For the above sample, determine the following measures:
a.
The mean.
b.
The standard deviation.
c.
The 25th percentile.
10
4. Exhibit 6-4: The starting salaries of individuals with an MBA degree are normally distributed
with a mean of $40,000 and a standard deviation of $5,000.
a.Refer to Exhibit 6-4. What is the random variable in this experiment?
b.Refer to Exhibit 6-4. What is the probability that a randomly selected individual with an MBA degree
will get a starting salary of at least $30,000?
c.Refer to Exhibit 6-4. What is the probability that a randomly selected individual with an MBA degree
will get a starting salary of at least $47,500?
11
5. A sample of 9 mothers was taken. The mothers were asked the age of their oldest child. You
are given their responses below.
a.
b.
c.
d.
e.
f.
g.
h.
3
12 4
7 14 6 2
9 11
Compute the mean.
Compute the variance.
Compute the standard deviation.
Compute the coefficient of variation.
Determine the 25th percentile.
Determine the median
Determine the 75th percentile.
Determine the range.
12
6. The following observations are given for two variables.
y
5
8
18
20
22
30
10
7
a.
b.
x
2
12
3
6
11
19
18
9
Compute and interpret the sample covariance for the above data.
Compute and interpret the sample correlation coefficient.
13