If you classified the fruit in a
basket as apple, orange, or banana, this would be an example of which level
of measurement?
A.interval
B.ordinal
C.ratio
D.nominal
Part 2 of 9 -
2.0/
2.0 Points
Question 2 of 25
1.0/
1.0 Points
If two events are mutually
exclusive, what is the probability that one or the other occurs?
A.0.25
B.Cannot
be determined from the information given.
C.0.50
D.1.00
Question 3 of 25
1.0/
1.0 Points
The staff at a small company includes:
4 secretaries, 20 technicians, 4 engineers, 2 executives, and 50 factory
workers. If a person is selected at random, what is the probability that he
or she is a factory worker?
A.5/8
B.2/5
C.1/8
D.1/4
An
Part 3 of 9 -
2.0/
3.0 Points
Question 4 of 25
1.0/
1.0 Points
A die is rolled 360 times. Find
the standard deviation for the number of 3s that will be rolled.
A.60
B.50
C.7.1
D.5.9
A
Question 5 of 25
1.0/
1.0 Points
A researcher surveyed college
students to study their opinion about the proposed change in smoking rules.
The researcher asked a group of 30 students: 12 of them supported the
change, 13 of them did not, and 5 had no opinion. This is not a binomial
model because...
A....the
students who strongly supported the change and those who only mildly
supported the change are counted the same.
B....less
than half of the students supported the change.
C.30
students are not enough for a good sample
D....there
are 3 possible outcomes, not 2.
Question 6 of 25
0.0/
1.0 Points
Suppose that 50 identical
batteries are being tested. After 8 hours of continuous use, assume that a
given battery is still operating with a probability of 0.70 and has failed
with a probability of 0.30.
What is the probability that greater than 30 batteries will last at least 8
hours?
A.0.0848
B.0.9152
C.0.8594
D.0.9522
Part 4 of 9 -
5.0/
6.0 Points
Question 7 of 25
1.0/
1.0 Points
One reason for standardizing
random variables is to measure variables with:
A.different
means and standard deviations on a non-standard scale
B.similar
means and standard deviations on two scales
C.dissimilar
means and similar standard deviations in like terms
D.different
means and standard deviations on a single scale
Answe
Question 8 of 25
1.0/
1.0 Points
If Z is a standard normal random
variable, then the value z for which P(-z < Z < z) equals 0.8764 is
A.3.08
B.1.54
C.0.3764
D.1.16
Question 9 of 25
1.0/
1.0 Points
In a normal distribution,
changing the standard deviation:
A.splits
the distribution to two curves
B.shifts
the curve left or right
C.makes
the curve more robust
D.makes
the curve more or less spread out
Question 10 of 25
1.0/
1.0 Points
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.0.1498
B.0.5328
C.0.3413
D.0.1915
Question 11 of 25
1.0/
1.0 Points
The continuous distribution
characterized by a symmetric, bell-shaped curve is the:
A.Poisson
distribution
B.binomial
distribution
C.normal
distribution
D.exponential
distribution
Question 12 of 25
0.0/
1.0 Points
The standard deviation of a
probability distribution is a:
A.measure
of skewness of the distribution
B.measure
of variability of the distribution
C.measure
of relative likelihood
D.measure
of central location
A
Part 5 of 9 -
1.0/
1.0 Points
Question 13 of 25
1.0/
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign
indicators (-), spaces (e.g., as thousands separator, 5 000), "E"
or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST
be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and
"b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas
{9i} is not.
A statistics professor has just
given a final examination in his statistical inference course. He is
particularly interested in learning how his class of 40 students performed
on this exam. The scores are shown below.
77
81
74
77
79 73
80
85
86 73
83
84
81
73
75 91
76
77
95 76
90
85
92
84
81 64
75
90
78 78
82
78
86
86
82 70
76
78
72 93
What is the mean score on this exam? Place your answer, rounded to
two decimal places in the blank. For example, 65.78 would be a legitimate
entry. 80.40
Part 6 of 9 -
1.0/
2.0 Points
Question 14 of 25
0.0/
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign
indicators (-), spaces (e.g., as thousands separator, 5 000), "E"
or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST
be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and
"b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas
{9i} is not.
The following data were obtained
from a survey of college students. The variable X represents the number of non-assigned books
read during the past six months.
x
0
1
2
3
4
5
6
P (X=x)
0.55
0.15
0.10
0.10
0.04
0.03
0.03
Find P(1 < X < 5). Place your answer, rounded to two decimal
places in the blank. For example, 0.56 would be a legitimate
entry. 1.14
Question 15 of 25
1.0/
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign
indicators (-), spaces (e.g., as thousands separator, 5 000), "E"
or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST
be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and
"b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas
{9i} is not.
In February 2002 the Argentine
peso lost 70% of its value compared to the United States dollar. This
devaluation drastically raised the price of imported
products. According to a survey conducted by AC Nielsen in April 2002,
68% of the consumers in Argentina were buying fewer products than before
the devaluation, 24% were buying the same number of products, and 8% were
buying more products. Furthermore, in a trend toward purchasing
less-expensive brands, 88% indicated that they had changed the brands they
purchased. Suppose the following complete set of results were
reported. Use the following data to answer this question.
Number of Products Purchased
Brands Purchased
Fewer
Same
More
Total
Same
10
14
24
48
Changed
262
82
8
352
Total
272
96
32
400
What is the probability that a consumer selected at random purchased fewer
products than before? Place your answer, rounded to 4 decimal places,
in the blank. 0.6800
Answer
Part 7 of 9 -
2.0/
2.0 Points
Part 8 of 9 -
4.0/
6.0 Points
Question 18 of 25
1.0/
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign
indicators (-), spaces (e.g., as thousands separator, 5 000), "E"
or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST
be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and
"b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas
{9i} is not.
Scores on a mathematics examination appear to follow a normal distribution
with mean of 65 and standard deviation of 15. The instructor wishes to give
a grade of “C” to students scoring between the 60th and 70th percentiles on
the exam.
What score represents the 70th percentile score on the mathematics exam?
Place your answer in the blank, rounded to a whole number. For example, 62
would be a legitimate entry. 73
Answer Key:
Question 19 of 25
1.0/
1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign
indicators (-), spaces (e.g., as thousands separator, 5 000), "E"
or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST
be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and
"b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas
{9i} is not.
Suppose that the average weekly earnings for employees in general
automotive repair shops is $450, and that the standard deviation for the
weekly earnings for such employees is $50. A sample of 100 such employees
is selected at random.
Find the probability that the mean of the sample is greater than $460.
Place your answer, rounded to 4 decimal places, in the blank. For example,
0.2345 would be a legitimate answer. 0.0228
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