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
Ans: B Difficulty level: low Objective: Explain what constitutes descriptive statistics.
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
Ans: A Difficulty level: low Objective: Explain what constitutes inferential statistics.
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
Ans: C Difficulty level: low Objective: Describe the difference between a population and a sample.
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
Ans: D Difficulty level: low Objective: Describe the difference between a population and a sample.
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
Ans: A Difficulty level: low Objective: Define the term "sample survey."
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
Ans: C Difficulty level: low Objective: Define the term "census."
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
Ans: A Difficulty level: low Objective: Explain what constitutes a representative sample from a population.
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
Ans: D Difficulty level: low Objective: Differentiate between a random sample and a nonrandom 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
Ans: C Difficulty level: low Objective: Differentiate between a random sample and a nonrandom 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
Ans: C Difficulty level: low Objective: Explain the meaning of a member, variable, measurement, and data set with reference to given tabular information.
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
Ans: B Difficulty level: low Objective: Explain the meaning of a member, variable, measurement, and data set with reference to given tabular information.
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
Ans: A Difficulty level: low Objective: Define the term "quantitative variable."
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
Ans: B Difficulty level: low Objective: Distinguish between discrete and continuous variables.
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
Ans: C Difficulty level: low Objective: Distinguish between discrete and continuous variables.
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
Ans: D Difficulty level: low Objective: "Define the term ""qualitative (or categorical) variable,"" providing practical examples."
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
Ans: A Difficulty level: low Objective: Define the term "time-series" data.
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
Ans: B Difficulty level: low Objective: Define the term "cross-section" data.
Use the following to answer questions 18-21:
The telephone bills for the past month for four families are $48, $65, $39, and $81.
18. The value of is:
Ans: 233
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
19. The value of is:
Ans: 14,611
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
20. The value of is:
Ans: 52,900
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
21. The value of is:
Ans: 210
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
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 is:
Ans: 412
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
23. The value of is:
Ans: 34,620
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
24. The value of is:
Ans: 169,744
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
25. The value of is:
Ans: 362
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
Use the following to answer questions 26-32:
Consider the following five pairs of m and f values:
26. The value of is:
Ans: 42
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
27. The value of is:
Ans: 232
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
28. The value of is:
Ans: 384
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
29. The value of is:
Ans: 159
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
30. The value of is:
Ans: 2,164
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
31. The value of is:
Ans: 1,370
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
32. The value of is:
Ans: 1,015
Difficulty level: medium Objective: Summation notation
Use the following to answer questions 33-39:
Consider the following six pairs of x and y values:
33. The value of is:
Ans: 102
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
34. The value of is:
Ans: 1,592
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
35. The value of is:
Ans: 34,802
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
36. The value of is:
Ans: 27,712
Difficulty level: low Objective: Perform elementary computations involving sigma notation and two variables.
37. The value of is:
Ans: 1,374
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
38. The value of is:
Ans: 2,080
Difficulty level: low Objective: Perform elementary computations involving sigma notation and one variable.
39. The value of is:
Ans: 24,101
Difficulty level: medium Objective: Perform elementary computations involving sigma notation and one variable.
40. Whether or not a university's enrollment increased from last year to this year is an example of qualitative or quantitative data?
Ans: Qualitative
Difficulty level: low Objective: Categorize variables as being quantitative or qualitative.
41. Total insect population among 12 U.S. national parks in 2003 is an example of time-series or cross-section data?
Ans: Cross-section
Difficulty level: low Objective: Categorize data as being cross-section data or time-series data.
42. Is the variable "lengths of top-ten hit songs" discrete or continuous?
Ans: Continuous
Difficulty level: low Objective: Distinguish between discrete and continuous variables.
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.
Ans: The statistician took the 20 largest countries. I representative sample should include some smaller countries also.
Difficulty level: medium Objective: Explain what constitutes a representative sample from a population.
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.
Ans: Census. She collected data from all 50 states in the population.
Difficulty level: medium Objective: Categorize data as being collected from a population or a sample.
45. Classify the following as cross-section or time-series data.
Monthly telephone bill for each family in an apartments complex.
Ans: Cross-section data
Difficulty level: medium Objective: Categorize data as being cross-section data or time-series data.
46. Classify the variable as discrete or continuous.
Duration of your last 30 cell phone calls.
Ans: Continuous
Difficulty level: low Objective: Distinguish between discrete and continuous variables.
47. The two types of variables are continuous and ______.
Ans: discrete
Difficulty level: low Objective: Distinguish between discrete and continuous variables.
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.
Ans: C Difficulty level: low Objective: Explain what constitutes a variable in a statistical study, identifying it in practical situations.
49. The Ohio lottery involves selecting 5 numbers from 5 different bins. This is an example of sampling
A) with replacement. B) without replacement.
Ans: A Difficulty level: low Objective: Explain the difference between random sampling with and without replacement.
50. The Megabucks lottery involves selecting 3 numbers from a single bin. This is an example of sampling
A) with replacement. B) without replacement.
Ans: B Difficulty level: low Objective: Explain the difference between random sampling with and without replacement.