Download Slide 1

1) The distribution of SAT Math scores of students taking
Calculus I at UTSA is skewed left with a mean of 625 and a
standard deviation of 44.5. If random samples of 100 students
are repeatedly taken, which statement best describes the
sampling distribution of sample means?
A) Shape is normal with a mean of 625 and standard deviation of 44.5.
B) Shape is normal with a mean of 625 and standard deviation of 4.45.
C) Shape unknown with a mean of 625 and standard deviation of 44.5.
D) Shape unknown with a mean of 625 and standard deviation of 4.45.
E) No conclusion can be drawn since the population is not normally
distributed.
2) A population has a normal distribution with a mean
of 50 and a standard deviation of 10. If a random
sample of size 9 is taken from the population, then
what is the probability that this sample mean will be
between 48 and 54?
A)0.000
D) 0.399
B) 0.228
E) 0.611
C) 0.385
3) Owners of a day-care chain wish to determine the proportion of families
in need of day care for the town of Sugar Land. The owners of the daycare chain randomly sample 50 families in Sugar Land and find only 4%
of the returned questionnaires indicate these families having a need for
child day-care services. The 4% is best described as
A) the sample proportion of families in Sugar Land needing child day-care
services.
B) the sample proportion of families in Sugar land with children needing
day-care services.
C) the population proportion of families in Sugar Land with children needing
day-care services.
D) the 30 families in Sugar Land needing day-care services for their
children.
E) the 600 families in Sugar Land with children needing day-care services.
4) In a hypothesis test, the decision between
a one-sided and two-sided alternative
hypothesis is based on:
A)Which one gives you a significant
result.
B) The alternative hypothesis appropriate
for the context of the problem.
C) How accurate you wish the results of
the test.
D) The level of significance of the test.
E) The statement of the null hypothesis.
5) A building inspector believes that the
percentage of new construction with serious
code violations may be even greater than
the previously claimed 7%. She conducts a
hypothesis test on 200 new homes and finds
23 with serious code violations. Is this
strong evidence against the .07 claim?
A) Yes, because the P-value is .0062.
B) Yes, because the P-value is 2.5.
C) No, because the P-value is only .0062
D) No, because the P-value is over 2.0.
E) No, because the P-value is .045
6) A survey is to be taken to estimate the proportion of
people who support the NATO decision to be actively
involved in the Balkins (assume sample proportion is
0.50). Among the following proposed sample sizes, which
is the smallest that will still guarantee a margin of error of
at most 0.03 for a 95% confidence level?
A)35
B) 70
D) 1100
E) 4300
C) 800
7) A manufacturer constructs a 95% confidence interval for the
proportion of successfully completed products off the assembly
line. His results need to be included in a report to his
supervisors, and the resulting interval is wider that he would
like. In order to decrease the size of the interval the MOST, the
manufacturer should take a new sample and
a) increase the confidence level and increase the sample size.
b) decrease the confidence level and increase the sample size.
c) increase the confidence level and decrease the sample size.
d) decrease the confidence level and decrease the sample size.
e) The manufacturer will not be able to decrease the size of the
interval.
8) A survey of 300 union members in New York State reveals that
112 favor the Republican candidate for governor. Construct a 98%
confidence interval for the percentage of all New York State union
members who favor the Republican candidate.
A) (31.9%, 42.8%)
B) (30.1%, 44.5%)
C) (26.7%, 47.9%)
D) (26.7%, 47.9%)
E) (30.8%, 43.8%)
9) A state university wants to increase its retention rate of 4% for graduating
students from the previous year. After implementing several new programs
during the last two years, the university reevaluates its retention rate and
comes up with a P-value of 0.075. What is reasonable to conclude about the
new programs using α = 0.06?
A) We can say there is a 7.5% chance of seeing the new programs having an effect
on retention in the results we observed from natural sampling variation. We conclude
the new programs are more effective.
B) There's only a 7.5% chance of seeing the new programs having no effect on retention
in the results we observed from natural sampling variation. We conclude the new
programs are more effective.
C) There is a 92.5% chance of the new programs having no effect on retention.
D) We can say there is a 7.5% chance of seeing the new programs having no effect on
retention in the results we observed from natural sampling variation. There is no
evidence the new programs are more effective, but we cannot conclude the new
programs have no effect on retention.
E) There is a 7.5% chance of the new programs having no effect on retention.
10) To plan the course offerings for the next year a university department dean needs to
estimate what impact the "No Child Left Behind" legislation might have on the teacher
credentialing program. Historically, 40% of this university's pre-service teachers have
qualified for paid internship positions each year. The Dean of Education looks at a
random sample of internship applications to see what proportion indicate the applicant
has achieved the content-mastery that is required for the internship. Based on these
data he creates a 90% confidence interval of (33%, 41%). Could this confidence interval
be used to test the hypothesis p = 0.40 versus p < 0.40 at the α = 0.05 level of
significance?
A) No, because the dean only reviewed a sample of the applicants instead of all of them.
B) Yes, since 40% is in the confidence interval he fails to reject the null hypothesis,
concluding that there is not strong enough evidence of any change in the percent of
qualified applicants.
C) No, because he should have used a 95% confidence interval.
D) Yes, since 40% is in the confidence interval he accepts the null hypothesis,
concluding that the percentage of applicants qualified for paid internship positions will
stay the same.
E) Yes, since 40% is not the center of the confidence interval he rejects the null
hypothesis, concluding that the percentage of qualified applicants will decrease.
11) M&M Corporation advertises that 20% of
the M&Ms produced will be orange in
color. However, when our class
experimented with these delightful treats
we found the percentage of orange to be
18.9%. The value 18.9% is a ______,
and the value 20% is a _____.
A. parameter, statistic
C. parameter, parameter
B. statistic, parameter
D. statistic, statistic
12) The distribution of values taken by a
statistic in all possible samples of the
same size from the same population is
the
A) probability that the statistic is obtained.
B) population parameter.
C) variance of the values.
D) sampling distribution of the statistic.
E) same shape as the population
distribution.
13) A factory produces plate glass with a mean
thickness of 4 mm and a standard deviation of
1.1 mm. A simple random sample of 100
sheets of glass is to be measured, and the
sample mean thickness of the 100 sheets is to
be computed. The probability that the average
thickness of the 100 sheets of glass is less
than 4.1 mm is
A. 0.8183
B. 0.5361
C. 0.1817
D. 0.6817
E. 0.8413
14) One month the actual unemployment rate in
France was 13.4% If during that month you took a
survey of 100 Frenchmen and constructed a
confidence interval estimate of the unemployment
rate, which of the following would be true?
I) The center of the interval was 13.4.
II) The interval contained 13.4.
III) 99% confidence interval estimate contained 13.4.
A. I and II
B. I and III
C. II and III
D. I, II, and III
E. None of the above gives the complete set of true
responses.
15)A photographer finds that 7% of all film
processed by a certain company will be
ruined. Find the probability that a
random sample of 81 rolls of film
processed by this company will contain
at most 5% of the rolls that are ruined?
A. 0.2580
B. 0.2611
C. 0.2389
D. 0.2420
E. none of these
16) Phil conducted a random survey of 1500
moviegoers and found that 650 of them really
enjoyed a particular movie. Construct a 90%
confidence interval for the true proportion of
moviegoers that really enjoy the particular
movie.
A. Between 41.2% and 45.4%
B. Between 40.8% and 45.8%
C. Between 58.8% and 54.6%
D. Between 59.1% and 54.2%
17) Which of the following are true statements?
I) The P-value of a test is the probability of
obtaining a result as extreme as the one
obtained assuming the null hypothesis is true.
II) If the P-value for a test is .015, the probability
that the null hypothesis is true is .015.
III) When the null hypothesis is rejected, it is
because it is not true.
A. I only
B. II only
C. III only
D. I and III
E. None of the above gives the complete set of
true responses.
• 18) Which of the following are true statements?
I. The larger the P-value, the more evidence there
is against the null hypothesis.
II. The alternative hypothesis is stated in terms of
a sample statistic.
III. If a sample is large enough, the necessity for it
to be a simple random sample is eliminated.
A. I only
B. II only
C. III only
D. Exactly two of the above statements are true.
E. None of the above statements are true.
Multiple Choice Review – Chapters 18, 19, 20
1)B
2)E
3) A
4) B
5) A
6) D
7) B
8) E
9) D
10) B
11) B
12) D
13) A
14) E
15) E
16) A
17) A
18) E