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Name_____________________________
Final Review
From: http://stattrek.com/AP-Statistics-1/Histogram.aspx?Tutorial=AP
1. Which of the following statements is true?
I. When the margin of error is small, the confidence level is high.
II. When the margin of error is small, the confidence level is low.
III. A confidence interval is a type of point estimate.
IV. A population mean is an example of a point estimate.
(A) I only
(B) II only
(C) III only
(D) IV only
(E) None of the above
2. Nine hundred (900) high school freshmen were randomly selected for a national survey. Among
survey participants, the mean grade-point average (GPA) was 2.7, and the standard deviation was
0.4. What is the margin of error, assuming a 95% confidence level?
(A) 0.013
(B) 0.025
(C) 0.500
(D) 1.960
(E) None of the above
3. Which of the following statements are true? (Check one)
I. A sample survey is an example of an experimental study.
II. An observational study requires fewer resources than an experiment.
III. The best method for investigating causal relationships is an observational study.
(A) I only
(B) II only
(C) III only
(D) All of the above
(E) None of the above
4. Suppose we want to estimate the average weight of an adult male in Dekalb County, Georgia. We
draw a random sample of 1,000 men from a population of 1,000,000 men and weigh them. We find
that the average man in our sample weighs 180 pounds, and the standard deviation of the sample is
30 pounds. What is the 95% confidence interval?
(A) 180 + 1.86
(B) 180 + 3.0
(C) 180 + 5.88
(D) 180 + 30
(E) None of the above
5. A major metropolitan newspaper selected a simple random sample of 1,600 readers from their
list of 100,000 subscribers. They asked whether the paper should increase its coverage of local
news. Forty percent of the sample wanted more local news. What is the 99% confidence interval for
the proportion of readers who would like more coverage of local news?
(A) 0.30 to 0.50
(B) 0.32 to 0.48
(D) 0.37 to 0.43
(C) 0.35 to 0.45
(E) 0.39 to 0.41
6. Suppose a simple random sample of 150 students is drawn from a population of 3000 college
students. Among sampled students, the average IQ score is 115 with a standard deviation of 10.
What is the 99% confidence interval for the students' IQ score?
(A) 115 + 0.01
(B) 115 + 0.82
(C) 115 + 2.1
(D) 115 + 2.6
(E) None of the above
7. Which of the following statements are true?
I. Random sampling is a good way to reduce response bias.
II. To guard against bias from undercoverage, use a convenience sample.
III. Increasing the sample size tends to reduce survey bias.
IV. To guard against nonresponse bias, use a mail-in survey.
(A) I only
(B) II only
(C) III only
(D) IV only
(E) None of the above
8. In hypothesis testing, which of the following statements are always true?
I. The P-value is greater than the significance level.
II. The P-value is computed from the significance level.
III. The P-value is the parameter in the null hypothesis.
IV. The P-value is a test statistic.
V. The P-value is a probability.
(A) I only
(B) II only
(C) III only
(D) IV only
(E) V only
9. The Acme Car Company claims that at most 8% of its new cars have a manufacturing defect. A
quality control inspector randomly selects 300 new cars and finds that 33 have a defect. Should she
reject the 8% claim? Assume that the significance level is 0.05.
(A) Yes, because the P-value is 0.016
(B) Yes, because the P-value is 0.028
(C) No, because the P-value is 0.16
(D) No, because the P-value is 0.28
(E) There is not enough information to reach a conclusion
10. Which of the following statements are true?
I. A completely randomized design offers no control for lurking variables.
II. A randomized block design controls for the placebo effect.
III. In a matched pairs design, subjects within each pair receive the same treatment.
(A) I only
(B) II only
(C) III only
(D) All of the above
(E) None of the above
11. Acme Corporation manufactures light bulbs. The CEO claims that an average Acme light bulb
lasts 300 days. A researcher randomly selects 15 bulbs for testing. The sampled bulbs last an
average of 290 days, with a standard deviation of 50 days. Use hypothesis testing to determine if
the CEO’s claim has any merit.
(A) Yes, because the P-value is 0.9602
(B) Yes, because the P-value is 0.4801
(C) No, because the P-value is 0.4801
(D) No, because the P-value is 0.4801
(E) There is not enough information to reach a conclusion
12. An archer claims that 25% of her shots will be in the center of the target (i.e., a bulls-eye). A
sports writer is not sure and thinks that maybe she should test this claim by sampling 300 shots.
She is worried that the archer is overestimating. Last time the archer took 300 shots in a row, she
hit 50 of them. Based on the trials last time, should the writer be worried about the archers claim?
(A) No, because the P-value is -3.2
(B) No, because the P-value is 0.0007
(C) Yes, because the P-value is -3.2
(D) Yes, because the P-value is 0.0007
(E) There is not enough information to reach a conclusion
13. Ms. Sweetwater's biology class had a standard deviation of 2.4 on a standardized test, while Ms.
Quincy's biology had a standard deviation of 1.2 on the same test. What can be said about these
two classes?
A. Ms. Sweetwater's class is more homogeneous than Ms. Quincy's.
B. Ms. Quincy's class is less heterogeneous than Ms. Sweetwater's.
C. Ms. Quincy's class did less well on the test than Ms. Sweetwater's.
D. Ms. Sweetwater's class performed twice as well on the test as Ms. Quincy's.
14. For a symmetric distribution, the mean and median are
A. the same
B. always different
C. possibly the same, possibly different
D. insufficient information.
15. Consider the following data: 1, 7, 3, 3, 6, 4
A. 4 and 3
B. 4.8 and 3 1/2
The mean and median for this data are:
C. 4 and 3 1/3
D. 4.8 and 3
E. 4 and 3 1/2
16. A distribution of 6 scores has a median of 21. If the highest score increases 3 points, the
median will become ___________.
A. 21
B. 21.5
C. 24
D. Cannot be determined without additional information.
17. The sample mean of the following sample is:
E. none of these
X
Frequency of X
A. 3
2
1
B. 2
3
2
C. 20
4
3
D. 20/9 = 2.22
E. 20/6 = 3.33
-----------------------------------------------------------------
18. If the mean, median and mode of a distribution are 5, 6, 7 respectively, then the distribution is:
A. skewed negatively
B. not skewed
D. symmetrical
C. skewed positively
E. bimodal.
19. Which of the following measures of central tendency tends to be most influenced by an extreme
score?
A. median
B. mode
C. mean
20. If the variance of a distribution is 9, the standard deviation is:
A. 3
B. 6
C. 9
D. 81
E. impossible to determine without knowing n.
21. What is the relationship between the variance of a set of scores and the standard deviation of
those scores?
A. variance = (standard deviation)^2
C. variance = mean/standard deviation
22. TABLE A
B. standard deviation = (variance)^2
D. standard deviation = mean/variance
The following table is a cross-tabulation of age and reading speed of 100 pupils.
Age to the nearest month
94-103
104-113
114-123
124-133
134-143
144-153 |
f(Y)
Score
on
reading
speed
|
46-51
4
1
| 5
40-45 2
10
5
| 17
34-39 1
5
2
| 8
28-33 2
8
6
3
1
1
| 21
22-27
9
13
3
| 25
16-21 1
5
4
2
1
1
| 14
10-15
2
3
3
1
1
| 10
------------------------------------------------------------f(X)
6
43
34
11
3
3
|100
In Table A, what proportion of those whose reading speed was more than 33 were aged between 104 and
113 months?
A. 19/30
B. 27/51
C 19/43
D. 27/43
E. 19/100
23. The median weight for a group of men is 65 kg; the mean is 75 kg. Based on your knowledge of
the mean and median would you expect the histogram for the group to look most like (a), (b), or (c)
below?
24. Suppose we would like to determine if the typical amount spent per customer for dinner at a
new restaurant in town is more than $20.00. A sample of 25 customers over a three-week period
was randomly selected and the average amount spent was $21.60. Assume that the standard
deviation is known to be $2.50. Would we conclude the typical amount spent per customer is more
than $20.00?
25. In a state election, Measure B needs 2/3 of the vote to pass. A qualified polling organization
finds that 64% of a random sample of 1,256 registered voters will vote for Measure B. Does this
suggest that the Measure will fail?
26. Suppose an editor of a publishing company claims that the mean time to write a textbook is at
most 15 months. A sample of 16 textbook authors is randomly selected and it is found that the
mean time taken by them to write a textbook was 13.5. Assume also that the standard deviation is
known to be 3.6 months. Assuming the time to write a textbook is normally distributed, would you
conclude the editor’s claim is true?