Question 13 of 251.0 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 7882 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. Question 14 of 251.0 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 and changed brands? Place your answer, rounded to 4 decimal places, in the blank. Question 15 of 251.0 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 school determines that the number of children X in the families who attend the school follows the distri.

1. Question 13 of 251.0 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 7882 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.
Question 14 of 251.0 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

2. 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
and changed brands? Place your answer, rounded to 4 decimal places, in the blank.
Question 15 of 251.0 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

3. stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A school determines that the number of children X in the families who attend the school follows
the distribution below:
Number of children X 1 2 3 4 5 Probability P(X) 0.20 0.35 0.25 0.15 0.05
What is the mean number of children per family? Round your answer to one decimal place as
necessary. For example, 4.5 would be a legitimate entry.
Question 16 of 251.0 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 probability experiment has two steps. There are two possible results for the first step, call
them "A" and "B". If the result for the first step was "A", then there would be 4 possible
results for the second step. If the result for the first step was "B", then there would be 16
possible results for the second step. How many possible outcomes are there for this
experiment? Place your answer in the blank. Do not use any decimal point or comma. For
example, 45 would be a legitimate entry.
Question 17 of 251.0 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 jar contains four white marbles, five red marbles, and six black marbles. If a marble was

4. selected at random, find the probability that it is white or black. Place your answer, rounded to 2
decimal places in the blank. For example 0.23 would be a legitimate entry.
Question 18 of 251.0 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 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.
What is the probability of getting a score between 65 and 89 on this exam? Place your answer,
rounded to 4 decimal places in the blank. For example, 0.3456 would be a legitimate entry.
Question 19 of 251.0 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 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 98% 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

5. Upper value
Question 20 of 251.0 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 mean of the sampling distribution of the means of average weekly earnings for samples
of size 100. Place your answer in the blank. Do not include a dollar sign. For example, 123
would be a legitimate entry.
Question 21 of 251.0 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 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
Question 22 of 251.0 Points

6. 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 length of time to complete a door assembly on an automobile factory assembly line is
normally distributed with mean 6.7 minutes and standard deviation 2.2 minutes. For a door
selected at random, what is the probability the assembly line time will be between 5 and 10
minutes? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776
would be a legitimate answer.
Question 23 of 251.0 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 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 between $20 and $35 at
this store? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456
would be a legitimate entry.
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.

7. 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 7882 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.
Question 14 of 251.0 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

8. 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
and changed brands? Place your answer, rounded to 4 decimal places, in the blank.
Question 15 of 251.0 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 school determines that the number of children X in the families who attend the school follows
the distribution below:
Number of children X 1 2 3 4 5 Probability P(X) 0.20 0.35 0.25 0.15 0.05
What is the mean number of children per family? Round your answer to one decimal place as

9. necessary. For example, 4.5 would be a legitimate entry.
Question 16 of 251.0 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 probability experiment has two steps. There are two possible results for the first step, call
them "A" and "B". If the result for the first step was "A", then there would be 4 possible
results for the second step. If the result for the first step was "B", then there would be 16
possible results for the second step. How many possible outcomes are there for this
experiment? Place your answer in the blank. Do not use any decimal point or comma. For
example, 45 would be a legitimate entry.
Question 17 of 251.0 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 jar contains four white marbles, five red marbles, and six black marbles. If a marble was
selected at random, find the probability that it is white or black. Place your answer, rounded to 2
decimal places in the blank. For example 0.23 would be a legitimate entry.
Question 18 of 251.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-),

10. 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.
What is the probability of getting a score between 65 and 89 on this exam? Place your answer,
rounded to 4 decimal places in the blank. For example, 0.3456 would be a legitimate entry.
Question 19 of 251.0 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 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 98% 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
Question 20 of 251.0 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.

11. 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 mean of the sampling distribution of the means of average weekly earnings for samples
of size 100. Place your answer in the blank. Do not include a dollar sign. For example, 123
would be a legitimate entry.
Question 21 of 251.0 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 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
Question 22 of 251.0 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 length of time to complete a door assembly on an automobile factory assembly line is

12. normally distributed with mean 6.7 minutes and standard deviation 2.2 minutes. For a door
selected at random, what is the probability the assembly line time will be between 5 and 10
minutes? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776
would be a legitimate answer.
Question 23 of 251.0 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 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 between $20 and $35 at
this store? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456
would be a legitimate entry.
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
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.

13. 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
and changed brands? Place your answer, rounded to 4 decimal places, in the blank.

14. 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
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.

15. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A school determines that the number of children X in the families who attend the school follows
the distribution below:
Number of children X 1 2 3 4 5 Probability P(X) 0.20 0.35 0.25 0.15 0.05
What is the mean number of children per family? Round your answer to one decimal place as
necessary. For example, 4.5 would be a legitimate entry.
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 probability experiment has two steps. There are two possible results for the first step, call
them "A" and "B". If the result for the first step was "A", then there would be 4 possible
results for the second step. If the result for the first step was "B", then there would be 16
possible results for the second step. How many possible outcomes are there for this
experiment? Place your answer in the blank. Do not use any decimal point or comma. For
example, 45 would be a legitimate entry.
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 jar contains four white marbles, five red marbles, and six black marbles. If a marble was
selected at random, find the probability that it is white or black. Place your answer, rounded to 2
decimal places in the blank. For example 0.23 would be a legitimate entry.
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:

16. 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.
What is the probability of getting a score between 65 and 89 on this exam? Place your answer,
rounded to 4 decimal places in the blank. For example, 0.3456 would be a legitimate entry.
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 98% 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
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

17. $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 mean of the sampling distribution of the means of average weekly earnings for samples
of size 100. Place your answer in the blank. Do not include a dollar sign. For example, 123
would be a legitimate entry.
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
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 length of time to complete a door assembly on an automobile factory assembly line is
normally distributed with mean 6.7 minutes and standard deviation 2.2 minutes. For a door
selected at random, what is the probability the assembly line time will be between 5 and 10

18. minutes? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776
would be a legitimate answer.
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 between $20 and $35 at
this store? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456
would be a legitimate entry.
Question 13 of 251.0 Points
Solution
Q 13.
Sum77817477797380858673785838481737591767795768119085928481647590787881782788
686827076787293803

19. Total3216
Mean80.4