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1.(TCO 9) The hours of study and
the final exam grades have this type of relationship:
= 7.35(hours) + 34.62. Based on this linear regression equation,
estimate the expected grade for a student spending 8 hours studying.
Round your answer to two decimal places. (Points : 6)

58.80
82.25
91.97
93.42

2.(TCO 5) At a drive through window
of a bank its found that 10 customers get served every 15 minutes. The
banks manage is interested in finding a way to increase the number of
customers that can be served. He thought that knowing the probability of
serving 12 customers per 15 minutes could be helpful to him in the
decision making process. Choose the best answer of the following: (Points : 6)

This is an
example of a Poisson probability experiment
This is an example of a Binomial probability
experiment
This is neither a Poisson nor a Binomial probability
experiment
Not enough information to determine the type of
experiment

3.(TCO 5) Microfracture knee
surgery has a 75% chance of success on patients with degenerative knees.
The surgery is performed on 5 patients. Find the probability of the
surgery being successful on 3 or 4 patients? (Points : 6)

0.103516
0.659180
0.762695
0.642875

4.(TCO 5) It has been recorded that
10 people get killed by shark attack every year. What is the probability
of having 7 or 8 people get killed by shark attack this year? (Points : 6)

0.130141
0.202678
0.220221
0.797321

5.(TCO 2) The median teaching hours
for a full time faculty at a state university is eight hours per week.
What does this tell you about the typical teaching hours for full time
faculty at that university? (Points : 6)

Half of the
full time faculties teach less than eight hours per week while half teaches
more than eight hours per week.
The average teaching hours for full time faculty is
eight hours per week.
More full time faculty teaches eight hours per week
than any other number of teaching hours.
The number of teaching hours for full time faculty in
not very consistent because eight is such a low number.

6.(TCO 6) Assuming that the data
are normally distributed with a mean of 25 and a standard deviation of
1.25, what is the z-score for a value of 27? (Points : 6)

2.30
1.60
3.10
-1.60

7.(TCO 8) The mean hours
of Internet usage by adults in the US in claimed to be 25 hours per week.
A hypothesis test is performed at a level of significance of
0.05 with a P-value of 0.08. Choose the best interpretation
of the hypothesis test. (Points : 6)

Reject the
null hypothesis; there is enough evidence to reject the claim that the mean
of hours Internet usage by adults in the US is 25 hours per week.
Reject the null hypothesis; there is enough evidence
to support the claim that the mean hours Internet usage by adults in the US
is 25 hours per week.
Fail to reject the null hypothesis; there is not
enough evidence to reject the claim that the mean hours of Internet usage
by adults in the US is 25 hours per week.
Fail to reject the null hypothesis; there is not
enough evidence to support the claim that the mean hours of Internet usage
by adults in the US is 25 hours per week.

8.(TCO 8) A result of an entry
level exam reveals that more than 22% of students fail that exam.
In a hypothesis test conducted at a level of significance of 2%, a P-value
of 0.035 was obtained. Choose the best interpretation of the
hypothesis test. (Points
: 6)

Fail to
reject the null hypothesis; there is not enough evidence to reject the
claim that 22% of students fail the entry level exam.
Fail to reject the null hypothesis; there is not
enough evidence to support the claim that 22% of students fail the entry
level exam.
Reject the null hypothesis; there is enough evidence
to reject the claim that 22% of students fail the entry level exam.
Reject the null hypothesis; there is enough evidence
to support the claim that 22% of students fail the entry level exam.

9.(TCO 2) You want to buy light
bulbs and you want to choose between two vendors. Vendor As light bulbs
have a mean life time of 800 hours and a standard deviation of 175 hours.
Vendor Bs light bulbs also have a mean life time of 800 hours, but a
standard deviation of 225 hours. You want light bulbs that have more life
time consistency, which vendor will you purchase from? (Points : 6)

Vendor A
because you will be more likely get light bulbs with the same life time
Vendor B because you will be more likely get light
bulbs with the same life time
Either one because both produce light bulbs with the
same mean life time.
Neither one because a mean height of 800 inches is
too short for a light bulb.

10.(TCO 4) A jar contains balls of
four different colors; red, blue, yellow and green. The total balls are
divides as 45% red, 35% blue, 15% yellow, and 5% green. If you are to
select one ball at random. Find the expected value of your winning amount
if the payments are set to be $5, $15, $25, $60 for red, blue, yellow and
green ball respectively.

Winning
amount

5

15

25

60

Probability

45%

35%

15%

5%

(Points :
6)

The
expected winning amount is $28.50
The expected winning amount is $14.25
The expected winning amount is $25.50
The expected winning amount is $11.25

11.(TCO 3) The grades of 20
students are listed below. Use the stem & leaf to determine the shape
of the distribution. Choose the best answer.
4 | 4
5 | 6 8
6 | 5 7 9
7 | 1 5 7 8 8 9
8 | 3 4 5 7 8 8 9
9 | 7
(Points :
6)

The data is
symmetric
The data is skewed to the right
The data is skewed to the left
The data is bimodal

12.(TCO 1) A researcher is
considering using 90% confidence interval for his research project
instead of 95%. What happens to the required sample size if the
confidence level is decreased from 95% to 90% and the same error margin
is allowed in each case? (Points : 6)

The sample
size remains unchanged
The sample size needs to increase
The sample size needs to decrease
Not enough information is provided to draw a
conclusion regarding the sample size in this case.

13.(TCO 6) Horse race time is found
to be normally distributed with a mean value of 18 minutes and a standard
deviation of 4 minutes. Horses whose race time is in the top 6% will not
be eligible to participate in a second round. What is the lowers race
time that makes a horse losses his eligibility to participate in a second
round? (Points
: 6)

26.6
11.8
24.2
20.3

14.(TCO 5) A class containing 25
students 12 of them are females. In how many ways can we select a group
of 6 male students? (Points
: 6)

1716
665280
1235520
924

15.(TCO 6) Research shows that the
life time of Everlast automobile tires is normally distributed with a
mean value of 65,000 miles and a standard deviation of 6,500 miles. What
is the probability of having a tire that lasts more than 75,000 miles? (Points : 6)

0.0618
1.54
0.9382
0.0606

16.(TCO 10) A research shows that
employee salaries at company XYX, in thousands of dollars, are given by
the equation y-hat= 48.5 + 2.2 a + 1.5 b where a is the years of
experience, and b is the education level in years. In thousands of
dollars, predict the salary for an employee with 7 years experience and
12 years education level. (Points : 6)

52.2
81.9
67.5
63.9

17.(TCO 9) Describe the correlation
in this graph.

(Points : 6)

moderate
positive
strong negative
moderate negative
strong positive

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Week 8 :

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1.(TCO 8) For the following
statement, write the null hypothesis and the alternative hypothesis. Also
label which one is the claim.
A car manufacturer claims that their cars makes at least 35 miles per
gallon of fuel. (Points :
8)

2.(TCO 11) A pizza restaurant manager
claims that the average home delivery time for their pizza is no more than
25 minutes. A random sample of 49 home delivery pizzas was collected. The
sample mean was found to be 26.5 minutes and the standard deviation was
found to be 4 minutes. Is there evidence to reject the managers claim at
alpha =.05? Perform an appropriate hypothesis test, showing the necessary
calculations and/or explaining the process used to obtain the results. (Points : 20)

3.(TCO 5) At a jewelry store, the
probability for a customer to make a purchase when entering the store is
35%. We asked 25 customers enter the store whether they made a purchase or
not.
(a) Is this a binomial experiment? Explain how you know.
(b) Use the correct formula to find the probability that, out of 25
customers, exactly 10 of them make a purchase. Show your calculations or
explain how you found the probability.
(Points :
20)

4.(TCO 6) The monthly utility bills
are normally distributed with a mean value of $130 and a standard deviation
of $15.
(a) Find the probability of having a utility bill between 100 and 150.
(b) Find the probability of having a utility bill less than $90.
(c) Find the probability of having a utility bill more than $160. (Points : 20)

5.(TCO 8) A Mall manager claims that
in average every customer spends $37 per a single visit to the mall. To
test this claim, you took a sample of 64 customers and found the sample
mean to be $34 and the sample standard deviation to be $5. At alpha = 0.05,
test the Malls manager claim. Perform an appropriate hypothesis test,
showing the necessary calculations and/or explaining the process used to
obtain the results. (Points :
20)

6.(TCO 7) A bank manager wanted to
estimate the mean number of transactions businesses make per month. For a
sample of 60 businesses, he found the mean number of transaction per month
to be 38 and the standard deviation to be 8.5 transactions.
(a) Find a 95% confidence interval for the mean number of business
transactions per month. Show your calculations and/or explain the process
used to obtain the interval.
(b) Interpret this confidence interval and write a sentence that explains
it. (Points :
20)

7.(TCO 7) A companys CEO wanted to
estimate the percentage of defective product per shipment. In a sample
containing 600 products, he found 45 defective products.

(a) Find a 99% confidence interval for the true proportion of defective
product. Show your calculations and/or explain the process used to obtain
the interval.
(b) Interpret this confidence interval and write a sentence that explains
it. (Points :
20)

8.(TCO 2) The ages of 10 students are
listed in years:{ 17,22,19,24,21,23,29,18,22,28 }

(a) Find the mean, median, mode, sample variance, and range.
(b) Do you think that this sample might have come from a normal population?
Why or why not? (Points :
20)

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Week 8 :

Top of FormTime
Remaining: Page:
1 2

Page 1

1.(TCO 9) The hours of study and
the final exam grades have this type of relationship:
= 7.35(hours) + 34.62. Based on this linear regression equation,
estimate the expected grade for a student spending 8 hours studying.
Round your answer to two decimal places. (Points : 6)
58.80
82.25
91.97
93.42

2.(TCO 5) At a drive through window
of a bank its found that 10 customers get served every 15 minutes. The
banks manage is interested in finding a way to increase the number of
customers that can be served. He thought that knowing the probability of
serving 12 customers per 15 minutes could be helpful to him in the
decision making process. Choose the best answer of the following: (Points : 6)
This is an
example of a Poisson probability experiment
This is an example of a Binomial probability
experiment
This is neither a Poisson nor a Binomial probability
experiment
Not enough information to determine the type of
experiment

3.(TCO 5) Microfracture knee
surgery has a 75% chance of success on patients with degenerative knees.
The surgery is performed on 5 patients. Find the probability of the
surgery being successful on 3 or 4 patients? (Points : 6)
0.103516
0.659180
0.762695
0.642875

4.(TCO 5) It has been recorded that
10 people get killed by shark attack every year. What is the probability
of having 7 or 8 people get killed by shark attack this year? (Points : 6)
0.130141
0.202678
0.220221
0.797321

5.(TCO 2) The median teaching hours
for a full time faculty at a state university is eight hours per week.
What does this tell you about the typical teaching hours for full time
faculty at that university? (Points : 6)
Half of the
full time faculties teach less than eight hours per week while half teaches
more than eight hours per week.
The average teaching hours for full time faculty is
eight hours per week.
More full time faculty teaches eight hours per week
than any other number of teaching hours.
The number of teaching hours for full time faculty in
not very consistent because eight is such a low number.

6.(TCO 6) Assuming that the data
are normally distributed with a mean of 25 and a standard deviation of
1.25, what is the z-score for a value of 27? (Points : 6)
2.30
1.60
3.10
-1.60

7.(TCO 8) The mean hours
of Internet usage by adults in the US in claimed to be 25 hours per week.
A hypothesis test is performed at a level of significance of
0.05 with a P-value of 0.08. Choose the best interpretation
of the hypothesis test. (Points : 6)
Reject the
null hypothesis; there is enough evidence to reject the claim that the mean
of hours Internet usage by adults in the US is 25 hours per week.
Reject the null hypothesis; there is enough evidence
to support the claim that the mean hours Internet usage by adults in the US
is 25 hours per week.
Fail to reject the null hypothesis; there is not
enough evidence to reject the claim that the mean hours of Internet usage
by adults in the US is 25 hours per week.
Fail to reject the null hypothesis; there is not
enough evidence to support the claim that the mean hours of Internet usage
by adults in the US is 25 hours per week.

8.(TCO 8) A result of an entry
level exam reveals that more than 22% of students fail that exam.
In a hypothesis test conducted at a level of significance of 2%, a P-value
of 0.035 was obtained. Choose the best interpretation of the
hypothesis test. (Points
: 6)
Fail to
reject the null hypothesis; there is not enough evidence to reject the
claim that 22% of students fail the entry level exam.
Fail to reject the null hypothesis; there is not
enough evidence to support the claim that 22% of students fail the entry
level exam.
Reject the null hypothesis; there is enough evidence
to reject the claim that 22% of students fail the entry level exam.
Reject the null hypothesis; there is enough evidence
to support the claim that 22% of students fail the entry level exam.

9.(TCO 2) You want to buy light
bulbs and you want to choose between two vendors. Vendor As light bulbs
have a mean life time of 800 hours and a standard deviation of 175 hours.
Vendor Bs light bulbs also have a mean life time of 800 hours, but a
standard deviation of 225 hours. You want light bulbs that have more life
time consistency, which vendor will you purchase from? (Points : 6)
Vendor A
because you will be more likely get light bulbs with the same life time
Vendor B because you will be more likely get light
bulbs with the same life time
Either one because both produce light bulbs with the
same mean life time.
Neither one because a mean height of 800 inches is
too short for a light bulb.

10.(TCO 4) A jar contains balls of
four different colors; red, blue, yellow and green. The total balls are
divides as 45% red, 35% blue, 15% yellow, and 5% green. If you are to
select one ball at random. Find the expected value of your winning amount
if the payments are set to be $5, $15, $25, $60 for red, blue, yellow and
green ball respectively.

Winning
amount5152560Probability45%35%15%5%(Points :
6)
The
expected winning amount is $28.50
The expected winning amount is $14.25
The expected winning amount is $25.50
The expected winning amount is $11.25

11.(TCO 3) The grades of 20
students are listed below. Use the stem & leaf to determine the shape
of the distribution. Choose the best answer.4 | 4
5 | 6 8
6 | 5 7 9
7 | 1 5 7 8 8 9
8 | 3 4 5 7 8 8 9
9 | 7(Points :
6)
The data is
symmetric
The data is skewed to the right
The data is skewed to the left
The data is bimodal

12.(TCO 1) A researcher is
considering using 90% confidence interval for his research project
instead of 95%. What happens to the required sample size if the
confidence level is decreased from 95% to 90% and the same error margin
is allowed in each case? (Points : 6)
The sample
size remains unchanged
The sample size needs to increase
The sample size needs to decrease
Not enough information is provided to draw a
conclusion regarding the sample size in this case.

13.(TCO 6) Horse race time is found
to be normally distributed with a mean value of 18 minutes and a standard
deviation of 4 minutes. Horses whose race time is in the top 6% will not
be eligible to participate in a second round. What is the lowers race
time that makes a horse losses his eligibility to participate in a second
round? (Points
: 6)
26.6
11.8
24.2
20.3

14.(TCO 5) A class containing 25
students 12 of them are females. In how many ways can we select a group
of 6 male students? (Points
: 6)
1716
665280
1235520
924

15.(TCO 6) Research shows that the
life time of Everlast automobile tires is normally distributed with a
mean value of 65,000 miles and a standard deviation of 6,500 miles. What
is the probability of having a tire that lasts more than 75,000 miles? (Points : 6)
0.0618
1.54
0.9382
0.0606

16.(TCO 10) A research shows that
employee salaries at company XYX, in thousands of dollars, are given by
the equation y-hat= 48.5 + 2.2 a + 1.5 b where a is the years of
experience, and b is the education level in years. In thousands of
dollars, predict the salary for an employee with 7 years experience and
12 years education level. (Points : 6)
52.2
81.9
67.5
63.9

17.(TCO 9) Describe the correlation
in this graph.

(Points : 6)
moderate
positive
strong negative
moderate negative
strong positive

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Remaining: Bottom of FormWeek 8 :

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page 2

1.(TCO 8) For the following
statement, write the null hypothesis and the alternative hypothesis. Also
label which one is the claim.
A car manufacturer claims that their cars makes at least 35 miles per
gallon of fuel. (Points :
8)
2.(TCO 11) A pizza restaurant manager
claims that the average home delivery time for their pizza is no more than
25 minutes. A random sample of 49 home delivery pizzas was collected. The
sample mean was found to be 26.5 minutes and the standard deviation was
found to be 4 minutes. Is there evidence to reject the managers claim at
alpha =.05? Perform an appropriate hypothesis test, showing the necessary
calculations and/or explaining the process used to obtain the results. (Points : 20)
3.(TCO 5) At a jewelry store, the
probability for a customer to make a purchase when entering the store is
35%. We asked 25 customers enter the store whether they made a purchase or
not.
(a) Is this a binomial experiment? Explain how you know.
(b) Use the correct formula to find the probability that, out of 25
customers, exactly 10 of them make a purchase. Show your calculations or
explain how you found the probability.
(Points :
20)
4.(TCO 6) The monthly utility bills
are normally distributed with a mean value of $130 and a standard deviation
of $15.
(a) Find the probability of having a utility bill between 100 and 150.
(b) Find the probability of having a utility bill less than $90.
(c) Find the probability of having a utility bill more than $160. (Points : 20)
5.(TCO 8) A Mall manager claims that
in average every customer spends $37 per a single visit to the mall. To
test this claim, you took a sample of 64 customers and found the sample
mean to be $34 and the sample standard deviation to be $5. At alpha = 0.05,
test the Malls manager claim. Perform an appropriate hypothesis test,
showing the necessary calculations and/or explaining the process used to
obtain the results. (Points :
20)
6.(TCO 7) A bank manager wanted to
estimate the mean number of transactions businesses make per month. For a
sample of 60 businesses, he found the mean number of transaction per month
to be 38 and the standard deviation to be 8.5 transactions.
(a) Find a 95% confidence interval for the mean number of business
transactions per month. Show your calculations and/or explain the process
used to obtain the interval.
(b) Interpret this confidence interval and write a sentence that explains
it. (Points :
20)
7.(TCO 7) A companys CEO wanted to
estimate the percentage of defective product per shipment. In a sample
containing 600 products, he found 45 defective products.

(a) Find a 99% confidence interval for the true proportion of defective
product. Show your calculations and/or explain the process used to obtain
the interval.
(b) Interpret this confidence interval and write a sentence that explains
it. (Points :
20)
8.(TCO 2) The ages of 10 students are
listed in years:{ 17,22,19,24,21,23,29,18,22,28 }

(a) Find the mean, median, mode, sample variance, and range.
(b) Do you think that this sample might have come from a normal population?
Why or why not? (Points :
20)
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