1. Under descriptive statistics, we study
A) the description of decision making tricks
B) the methods for organizing, displaying, and describing data
C) how to describe the probability distribution
D) samples to assist in decision making
2. Under inferential statistics, we study
A) the methods to make decisions about one or more populations based on sample
results
B) how to make decisions about a mean, median, or mode
C) how a sample is taken from a population
D) tables composed of summary measures
3. In statistics, a population consists of:
A) all people living in a country
B) all people living in the area under study
C) all subjects or objects whose characteristics are being studied
D) a selection of a limited number of elements
4. In statistics, we define a sample as:
A) people living in one city only C) all items under investigation
B) the target population D) a portion of the population
5. In statistics, conducting a survey means:
A) collecting information from elements C) drawing pictures and graphs
B) making mathematical calculations D) none of these
6. In statistics, conducting a census means:
A) making decisions based on sample results
B) checking if a variable is qualitative or quantitative
C) collecting information from all members of the population
D) collecting a sample with replacement
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7. In statistics, a representative sample is a sample that:
A) contains the characteristics of the population as closely as possible
B) represents the results of a sample exactly
C) contains all people living in an area
D) contains elements collected with replacement
8. A random sample is a sample drawn in such a way that:
A) each member of the population has a 0.10 chance of being included in the sample
B) all elements of a population are included
C) some members of the population have no chance of being included in the sample
D) each member of the population has some chance of being included in the sample
9. A simple random sample is a sample drawn in such a way that:
A) each member of the population has some chance of being included in the sample
B) every tenth element of an arranged population is included
C) each sample of the same size has an equal chance of being selected
D) each member of the population has a 0.10 chance for being included in the sample
10. A data set is a:
A) set of decisions made about the population
B) set of graphs and pictures
C) collection of observations on one or more variables
D) score collected from an element of the population
11. An observation is a:
A) graph observed for a data set
B) value of a variable for a single element
C) table prepared for a data set
D) sample observed from the population
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12. A quantitative variable is the only type of variable that can:
A) assume numeric values for which arithmetic operations make sense
B) be graphed
C) be used to prepare tables
D) have no intermediate values
13. A discrete variable is a variable that can assume:
A) categorical values only C) an uncountable set of values
B) a countable set of values only D) non-numerical values
14. A continuous variable is a variable that can assume:
A) categorical values only C) an uncountable set of values
B) a countable set of values only D) non-numerical values
15. A qualitative variable is the only type of variable that:
A) can assume numerical values
B) cannot be graphed
C) can assume an uncountable set of values
D) cannot be measured numerically
16. Time-series data are collected:
A) on the same element for the same variable at different points in time
B) on a variable that involves time, e.g., minutes, hours, weeks, months, etc.
C) for a qualitative variable
D) on different elements for the same period of time
17. Cross-section data are collected:
A) on the same variable for the same variable at different points in time
B) on different elements at the same point in time
C) for a qualitative variable
D) on different elements for the same variable for different periods of time
Use the following to answer questions 18-21:
The telephone bills for the past month for four families are $48, $65, $39, and $81.
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18. The value of
x
is:
19. The value of
2
x
is:
20. The value of
( )
2
x
is:
21. The value of
( )
5x−
is:
Use the following to answer questions 22-25:
The test scores of five students are 85, 64, 95, 75, and 93.
22. The value of
x
is:
23. The value of
2
x
is:
24. The value of
( )
2
x
is:
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25. The value of
( )
10x−
is:
Use the following to answer questions 26-32:
Consider the following five pairs of m and f values:
m
f
6
3
9
5
7
5
13
6
7
8
26. The value of
is:
27. The value of
mf
is:
28. The value of
2
m
is:
29. The value of
2
f
is:
30. The value of
2
mf
is:
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31. The value of
2
mf
is:
32. The value of
( )
2
3mf−
is:
Use the following to answer questions 33-39:
Consider the following six pairs of x and y values:
x
y
8
10
11
16
15
20
5
7
20
28
21
21
33. The value of
y
is:
34. The value of
xy
is:
35. The value of
2
xy
is:
36. The value of
2
xy
is:
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37. The value of
2
x
is:
38. The value of
2
y
is:
39. The value of
2
( 2)xy−
is:
40. Whether or not a university’s enrollment increased from last year to this year is an
example of qualitative or quantitative data?
41. Total insect population among 12 U.S. national parks in 2003 is an example of
time-series or cross-section data?
42. Is the variable “lengths of top-ten hit songs” discrete or continuous?
43. A statistician wants to determine the average annual Gross National Product for countries
in Africa. He samples the 20 largest (in terms of population) African countries over 10
years, and gets their quarterly G.N.P results for each quarter of each year. The statistician
is criticized because the sample is not representative. Explain why.
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44. A statistician wants to determine the total annual medical costs incurred by all U.S. states
from 1981 to 2001 as a result of health problems related to smoking. She polls each of the
50 states annually to obtain health care expenditures, in dollars, on smoking-related
illnesses. Does this study constitute a survey or a census. Explain.
45. Classify the following as cross-section or time-series data.
Monthly telephone bill for each family in an apartments
complex.
46. Classify the variable as discrete or continuous.
Duration of your last 30 cell phone calls.
47. The two types of variables are continuous and ______.
48. An independent group wants to determine if the consumption of gasoline has increased
due to changes in price. The group randomly selects 320 gas stations from 12 different
states and collects data from the month of the year when gas is the cheapest and from the
month of the year when gas is the most expensive. The data shows no significant
difference in gas consumption between the two months.
In this example, what is the variable being studied?
A) The 320 gas stations chosen. C) The consumption of gasoline.
B) The 12 different states. D) The price of gasoline.
49. The Ohio lottery involves selecting 5 numbers from 5 different bins. This is an example
of sampling
A) with replacement. B) without replacement.
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50. The Megabucks lottery involves selecting 3 numbers from a single bin. This is an
example of sampling
A) with replacement. B) without replacement.