(TCO 9) The
hours of study and the final exam grades have this type of relationship:
ลท =
5.76(hours) + 35.31. 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)
46.08
81.39
91.45
85.29
2. (TCO 5)
At a drive through window of a bank it’s found that 10 customers get served
every 15 minutes. The bank’s 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 more than 3 patients? (Points :
6)
0.487304
0.367188
0.632813
0.762695
4. (TCO 5)
It has been recorded that 10 people get killed by shark attack every year. What
is the probability of having 5 or 6 people get killed by shark attack this
year? (Points : 6)
0.130141
0.026484
0.100889
0.067086
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 22% of students fail that exam.
In a
hypothesis test conducted at a level of significance of 2%, a P-value of 0.045
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)
A bank is going to choose between two systems A and B which helps in measuring
customers waiting time. During the trial period, both systems showed an average
waiting time of 10 minutes. Type A showed a standard deviation of 2 minutes
while type B showed a standard deviation of 4 minutes. Which of the two systems
the bank should choose? (Points : 6)
System A
because in shows more consistency in measuring the average waiting time.
System B
because in shows more consistency in measuring the average waiting time.
Either
because their mean waiting time is the same in both systems.
Neither
because the given information is not enough to make a decision
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 in the stem and leaf diagram below. What
is the probability of randomly selected student to have a grade more than or
equal to 60 and less than or equal to 80.
4 | 4
5 | 6 8
6 | 5 7 9
7 | 1 5 7 8
8 9
8 | 0 2 5 7
8 8 9
9 | 7
(Points : 6)
0.65
0.50
0.45
-0.55
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 10
minutes and a standard deviation of 2 minutes. Horses whose race time is in the
top 5% 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)
13.29
12
6.71
15.29
14. (TCO 5)
A class containing 20 students 8 of them are females. In how many ways can we
select a group of 5 male students?(Points : 6)
56
792
6720
95040
15. (TCO 6)
Research shows that the life time of Everlast automobile tires is normally
distributed with a mean value of 60,000 miles and a standard deviation of 5,000
miles. What is the probability of having a tire that lasts more than 67,000
miles? (Points : 6)
0.9192
0.0808
1.40
0.0793
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 10 years experience and 14
years education level. (Points : 6)
52.2
72.5
70.5
91.5
17. (TCO 9)
Describe the correlation in this graph.
