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Question 1 of 25
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1.0 Points
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An
advertisement for a car states that it is 10% more powerful than its
competitor. This is an example of
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A.ambiguous
averages
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B.changing
the subject
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C.suspect
samples
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D.detached
statistics
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Question 2 of 25
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1.0 Points
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A
furniture manufacturer offers bookcases in 5 different sizes and 3 different
colors. If every color is available in every size, then the total number of
different bookcases is
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Question 3 of 25
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1.0 Points
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If
two events are mutually exclusive, what is the probability that both occur
at the same time?
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A.1.00
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B.Cannot
be determined from the information given.
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C.0.00
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D.0.50
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Question 4 of 25
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1.0 Points
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In
one town 33% of the households have a vehicle with all-wheel drive. If 4
households are selected at random, what is the probability that all 4 have
vehicles with all-wheel drive?
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A.0.4662
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B.0.0825
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C.0.0119
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D.0.33
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Question 5 of 25
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1.0 Points
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Which
term is NOT synonymous with the expected value of a discrete probability distribution?
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A.variance
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B.mean
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C.μ
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D.theoretical
average
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Question 6 of 25
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1.0 Points
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Find the variance of the
following probability distribution.
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X
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P(X)
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1
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0.30
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2
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0.15
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3
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0.05
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4
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0.25
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5
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0.25
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A.1.73
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B.1.61
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C.2.60
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D.1.27
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Question 7 of 25
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1.0 Points
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If
Z is a standard normal random variable, the area between z = 0.0 and z
=1.30 is 0.4032, while the area between z = 0.0 and z = 1.50 is 0.4332.
What is the area between z = -1.30 and z = 1.50?
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A.0.0300
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B.0.0968
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C.0.8364
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D.0.0668
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Question 8 of 25
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1.0 Points
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The
standard deviation of a probability distribution must be:
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A.less
than the value of the mean
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B.a
negative number
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C.a
nonnegative number
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D.a
number between 0 and 1
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Question 9 of 25
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1.0 Points
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If
the value of the standard normal random variable Z is positive, then the
original score is where in relationship to the mean?
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A.equal
to the mean
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B.one
standard deviation higher than the mean
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C.to
the left of the mean
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D.to
the right of the mean
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Question 10 of 25
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1.0 Points
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The
mean of a probability distribution is a:
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A.measure
of skewness of the distribution
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B.measure
of central location
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C.measure
of relative likelihood
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D.measure
of variability of the distribution
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Question 11 of 25
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1.0 Points
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The
standard deviation of a probability distribution is a:
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A.measure
of central location
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B.measure
of relative likelihood
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C.measure
of variability of the distribution
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D.measure
of skewness of the distribution
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Question 12 of 25
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1.0 Points
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The
theorem that states that the sampling distribution of the sample mean is
approximately normal when the sample size n is reasonably large is known as
the:
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A.point
estimate theorem
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B.central
tendency theorem
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C.simple
random sample theorem
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D.central
limit theorem
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Question 13 of 25
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1.0 Points
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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 histogram below represents scores achieved by 250 job applicants on a
personality profile.
What percentage of the job applicants scored between 30 and 40? Place
your answer in the blank, rounded to 2 decimal places. Do not use a
percentage sign (%). For example, 44.44 would be a legitimate answer.
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Question 14 of 25
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1.0 Points
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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 a survey, 55% of the voters support a particular referendum. If 40
voters are chosen at random, and X is the number of voters that support
this referendum, find the mean and variance of X. Place the mean in the
first blank and place the variance in the second blank.
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Question 15 of 25
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1.0 Points
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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.
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x
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0
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1
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2
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3
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4
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5
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6
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P (X=x)
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0.55
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0.15
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0.10
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0.10
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0.04
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0.03
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0.03
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Find P(X > 0). Place your answer, rounded to two decimal places in
the blank. For example, 0.56 would be a legitimate entry.
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Question 16 of 25
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1.0 Points
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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
restaurant menu has a price-fixed complete dinner that consists of an appetizer,
entrée, beverage, and dessert. You have a choice of five appetizers,
ten entrees, three beverages, and six desserts. How many possible
complete dinners are possible? Place your answer, as a whole number—no
decimal places—in the blank. For example 176 would be a legitimate entry
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Question 17 of 25
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1.0 Points
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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.
An urn contains 12 balls identical in every respect except their color.
There are 3 red balls, 7 green balls, and 2 blue balls. You draw two balls
from the urn, but replace the first ball before drawing the second. Find
the probability that the first ball drawn is red and the second ball drawn
is green. Place your answer, rounded to 4 decimal places, in the blank. For
example, 0.4567 would be a legitimate entry.
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Question 18 of 25
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1.0 Points
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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.
Mrs.
Smith’s reading class can read a mean of 175 words per minute with a
standard deviation of 20 words per minute. The top 3% of the class is
to receive a special award. Assuming that the distribution of words read
per minute are normally distributed, what is the minimum number of words
per minute a student would have to read in order to get the
award? Place your answer, rounded to the nearest whole number,
in the blank. When entering your answer do not use any labels or
symbols. Simply provide the numerical value. For example, 123
would be a legitimate entry.
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Question 19 of 25
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1.0 Points
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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 probability that the mean of the sample is less than $445. Place your
answer, rounded to 4 decimal places, in the blank. For example, 0.2345
would be a legitimate entry.
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Question 20 of 25
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1.0 Points
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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 popular retail store knows that the purchase amounts by its customers is
a random variable that follows a normal distribution with a mean of $30 and
a standard deviation of $9.
What is the probability that a randomly selected customer will spend $20 or
more at this store? Place your answer, rounded to 4 decimal places, in the
blank. For example, 0.3456 would be a legitimate entry.
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Question 21 of 25
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1.0 Points
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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 between $445 and $455.
Place your answer, rounded to 4 decimal places, in the blank. For example,
0.2345 would be a legitimate entry.
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Question 22 of 25
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1.0 Points
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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 set of final exam scores in an organic chemistry course was found to be
normally distributed, with a mean of 73 and a standard deviation of 8.
Only 5% of the students taking the test scored higher than what value?
Place your answer, rounded to a whole number, in the blank. For example, 78
would be a legitimate entry.
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Question 23 of 25
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1.0 Points
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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 popular retail store knows that the purchase amounts by its customers is
a random variable that follows a normal distribution with a mean of $30 and
a standard deviation of $9.
What are the two dollar amounts, equidistant from the mean of $30, such
that 90% of all customer purchases are between these values? Place your
answers in the blanks provided. Do not include a dollar sign. For example,
14.25 would be a legitimate entry.
Lower value
Upper value
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Question 24 of 25
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1.0 Points
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Using
the standard normal curve, the Z- score representing the 5th percentile is
1.645.
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Question 25 of 25
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1.0 Points
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Using
the standard normal curve, the Z- score representing the 99th percentile is
2.326.
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