(TCO 1. 9) The hours of study and the final exam grades have this type of relationship:
= 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) Historical sales records show that 40% of all customers who enter a
discount department store make a purchase. We are interested in calculating the
probability that 3 of 5 customers make purchase. 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 mode 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 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 less
than 25 hours per week. A hypothesis test is performed at a level of significance of
0.05 with a P-value of 0.11. 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.
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 0.0128
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 not is 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) Having two types of cars called type A and type B. In observing the miles
per gallon we found that both types make mean miles per gallon of 32. Car A has a
standard deviation of 5 miles per gallon while car B has a standard deviation of 3
miles per gallon. Which of the two car types is more consistent in fuel consumption?
(Points : 6)
Type A car because it got more fuel consumption consistency.
Type B car because it got more fuel consumption consistency.
Either car type because their average fuel consumption is the same.
Neither car type 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 40% red, 30% blue, 20% yellow, and 10% 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, $10, $20, $50 for red, blue, yellow and green ball respectively.
Winning amount
5
10
20
50
Probability
40%
30%
20%
10%
(Points : 6)
The expected winning amount is $12
The expected winning amount is $25
The expected winning amount is $14
The expected winning amount is $40
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|68
6|579
7|157889
8|3457889
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 interested in studying peoples mean age in a certain region. If
the population standard deviation is known to be 8 years and 1.5 year of error margin is
allowed, find the minimum simple size the researcher needs to use, knowing that he is going
to conduct his study using 95% confidence level. (Points : 6)
Sample Size = 77
Sample Size = 25
Sample Size = 210
Sample Size = 110
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 15 students 5 of them are females. In how many ways can we
select a group of 4 male students? (Points : 6)
260
120
5040
210
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