Part 1 of 9 -

Question 1 of 25

1.0 Points

Which of the following are the three most common measures of central location?

A.Mean, median, and variance
B.Mean, variance, and standard deviation
C.Mean, median, and mode
D.Mean, median, and standard deviation

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Part 2 of 9 -

Question 2 of 25

1.0 Points

If A and B are any two events with P(A) = .8 and P(B|A) = .4, then the joint probability of A and B is

A.0.32
B.1.20
C.0.40
D.0.80

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Question 3 of 25

1.0 Points

What type of probability uses sample spaces to determine the numerical probability that an event will occur?

A.empirical probability
B.subjective probability
C.classical probability
D.conditional probability

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Part 3 of 9 -

Question 4 of 25

1.0 Points

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
P (X=x)	0.20	0.25	0.20	0.15	0.10	0.10

Find P( X 5)

A.0.90
B.0.10
C.1.00
D.0.20

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Question 5 of 25

1.0 Points

A discrete probability distribution:

A.can be estimated from long-run proportions
B.is a tool that can be used to incorporate uncertainty into models
C.is the distribution of multiple random variables
D.lists all of the possible values of the random variable and their corresponding probabilities

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Question 6 of 25

1.0 Points

Find the variance of the following probability distribution.

X	P(X)
1	0.30
2	0.15
3	0.05
4	0.25
5	0.25

A.1.73
B.1.61
C.2.60
D.1.27

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Part 4 of 9 -

Question 7 of 25

1.0 Points

The standard deviation of a probability distribution must be:

A.a negative number
B.a nonnegative number
C.less than the value of the mean
D.a number between 0 and 1

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Question 8 of 25

1.0 Points

The standard normal distribution has a mean of ___ and standard deviation of ___, respectively.

A.1 and 0
B.0 and 0
C.1 and 1
D.0 and 1

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Question 9 of 25

1.0 Points

The normal distribution is:

A.a density function of a discrete random variable
B.a binomial distribution with only one parameter
C.a discrete distribution
D.the single most important distribution in statistics

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Question 10 of 25

1.0 Points

If Z is a standard normal random variable, the area between z = 0.0 and z .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?

A.0.8364
B.0.0968
C.0.0300
D.0.0668

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Question 11 of 25

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.0.3764
B.3.08
C.1.54
D.1.16

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Question 12 of 25

1.0 Points

The mean of a probability distribution can be:

A.a positive number
B.a negative number
C.zero
D.all of the above

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Question 13 of 25

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 are the base salaries, in thousands of dollars, of 50 chief executive officers for a sample of companies doing business with the state of Connecticut. That is, the first entry in the table below corresponds to a salary of $125,000. A copy of this data set can be found in the Excel Workbook called CEOSalaries.xls.

125	157	113	127	201
165	145	119	148	158
148	168	117	105	136
136	125	148	108	178
179	191	225	204	104
205	197	119	209	157
209	205	221	178	247
235	217	222	224	187
265	148	165	228	239
245	152	148	115	150

Find the mean of the CEO salaries, in thousands of dollars, rounded to 2 decimal places. Do not use a dollar sign. Note: $177,760 should be recorded as 177.76.

CEOSalaries.xls

Question 14 of 25

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.

Find the mean of the following probability distribution.

X	1	2	3	4	5
P(X)	0.20	0.10	0.35	0.05	0.30

Round your answer to two decimal place as necessary. For example, 4.56 would be a legitimate entry.

Mean =

Question 15 of 25

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.

Ann is applying for a bank loan to open a pizza franchise. She must first complete a written application and then, if the written application is approved, be interviewed by bank officers. If an applicants written application is not approved the applicant is not granted an interview with the bank officers. Past records for this bank show that the probability of an applicant having his or her written application approved is 0.63. Records also indicate that the interviewing committee of bank officers approves 85% of the individuals they interview. Find the probability that Anns loan request is approved. Place your answer, rounded to 2 decimal places, in the blank. For example, 0.76 would be a legitimate entry.

Part 7 of 9 -

Question 16 of 25

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 restaurant menu has a price-fixed complete dinner that consists of an appetizer, entre, 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 numberno decimal placesin the blank. For example 176 would be a legitimate entry

Question 17 of 25

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.

At a certain college, there were 600 science majors, 200 engineering majors, and 500 business majors. If a student is selected at random, what is the probability that the student is an engineering major?

Place your answer, rounded to four decimal places, in the blank. When entering your answer do not use any labels or symbols other than a decimal point. Simply provide the numerical value. For example, 0.1234 would be a legitimate entry.

Question 18 of 25

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 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 19 of 25

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 Wendys fast-food restaurant sells hamburgers and chicken sandwiches. On

a typical weekday, the demand for hamburgers is normally distributed with a mean

of 450 and standard deviation of 80 and the demand for chicken sandwiches is

normally distributed with a mean of 120 and standard deviation of 30.

How many chicken sandwiches must the restaurant stock to be 99% sure of not

running out on a given day? Place you answer, rounded to the nearest whole

number in the blank. For example, 345 would be a legitimate entry.

Question 20 of 25

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 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 of 91 or less on this exam?

Place your answer, rounded to 4 decimal places in the blank.

For example, 0.3456 would be a legitimate entry.

Question 21 of 25

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 average hourly wage of workers at a fast food restaurant is $6.50/hr with

a standard deviation of $0.45. Assume that the distribution is normally distributed.

If a worker at this fast food restaurant is selected at random, what is the probability

that the worker earns more than $6.75? Place your answer, rounded to 4 decimal

places, in the blank. For example, 0.1776 would be a legitimate entry.

Question 22 of 25

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 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.

Question 23 of 25

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 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 24 of 25

1.0 Points

Using the standard normal curve, the Z- score representing the 75th percentile is approximately 0.674.

True or False

Question 25 of 25

1.0 Points

Using the standard normal curve, the probability or area between Z = -1.50 and Z = 1.50 is 0.4332.

True or False