15 Jan d. proportions.

DATA205 Introductory Analytics (QC)

Quiz 1 Chapters 1-2

Question 1A discrete variable cannot be

Answers:

a. observed.

b. multiplied.

c. added.

d. subdivided.

Question 2A researcher has numbered all 50 states from 1 to 50 and has calculated a mean of 17.43 for the variable “state of birth.”

is interval-ratio and the mean is an appropriate and useful statistic in this case.

Answers:

a. Since the variable is ordinal, we should treat the value of the mean with great caution.

b. The variable is interval-ratio and the mean is an appropriate and useful statistic in this case.

c. Since this variable is discrete, the mean should not be computed.

d. Since the variable is nominal, the mean makes no sense.

Question 3According to the “Wheel of Science,” research projects begin

Answers:

a. with an hypothesis.

b. at any stage on the Wheel.

c. with data.

d. with theory.

Question 4An hypothesis states, in part, that “income increases as education increases”. In this statement, education is

Answers:

a. the secondary variable.

b. the dependent variable.

c. the independent variable.

d. the hypothetical variable.

Question 5Categories of nominal level variables should be everything except

Answers:

a. mutually exclusive to avoid ambiguity in classifying cases.

b. exhaustive so that every case fits into a category.

c. relevant to the research goals.

d. All of the above

Question 6Data is the same thing as

Answers:

a. statistics.

b. proof.

c. information collected in numerical form.

d. information collected in any form.

Question 7If a researcher summarizes the age of 1,000 people by calculating the average age, she is using

Answers:

a. data reduction.

b. an incorrect hypothesis.

c. a qualitative technique.

d. non-empirical reasoning.

Question 8In addition to saying that one case is different from another, the ordinal level of measurement allows us to

Answers:

a. put cases in general categories.

b. measure the distance between high and low.

c. say that one case is more or less than another.

d. calculate meaningful averages of variables.

Question 9In time, the ____________ variable precedes the _____________ variable.

Answers:

a. dependent, independent

b. discrete, continuous

c. independent, dependent

d. hypothetical, theoretical

Question 10On a test, the numbers used to identify the questions would be __________ in level of measurement while the number of correct responses would be _____________.

Answers:

a. ordinal, nominal

b. nominal, interval-ratio

c. continuous, discrete

d. interval-ratio, nominal

Question 11When using interval-ratio data, the distance between the scores is

Answers:

a. always two units.

b. exactly defined.

c. not always clear.

d. unequal.

Question 12Which of the following is a continuous variable?

Answers:

a. Number of times you have changed residences within the last five years

b. Number of meals you consumed yesterday

c. Number of children

d. Time spent watching TV

Question 13Which of the following is a discrete variable?

Answers:

a. Height

b. Age

c. Number of children

d. Miles per gallon

Question 14?A _____ is the number of times a phenomena occurs divided by the total possible occurrences.

Answers:

a. ?histogram

b. ?ratio

c. ?rate

d. ?frequency distribution

Question 15A police department reports that the number of reported rapes in their jurisdiction increased by 100% over the past decade. This means that the number of reported rapes today is

Answers:

a. equal to the number 10 years ago plus 50%.

b. double the number 10 years ago.

c. actually about the same as 10 years ago.

d. triple the number 10 years ago.

Question 16

TABLE 2.2 AGES OF RESPONDENTS

Class Intervals

Frequency

Percentages

?18-23

5

?

24-29

21

?

?30-40

10

?

TOTAL

36

A possible problem with Table 2.2 is that

Answers:

a. class intervals overlap.

b. class intervals are exhaustive.

c. class intervals are too large.

d. class intervals are unequal in size.

Question 17Cumulative frequencies and cumulative percentages allow a researcher to

Answers:

a. be sure the column totals are correct.

b. tell at a glance how many cases fall above or below a given category.

c. show the accuracy of his or her findings.

d. All of the above

Question 18For a single variable measured at the nominal level, an appropriate graph would be a

Answers:

a. frequency polygon.

b. histogram.

c. bivariate table

d. pie chart.

Question 19Frequency distributions may be compiled for variables measured at which level?

Answers:

a.Nominal

b. Ordinal

c. Interval-ratio

d. All of the above

Question 20Histograms and line charts or frequency polygons are used with data measured at the

Answers:

a. ordinal level.

b. nominal level.

c. any level.

d. interval-ratio level.

Question 21Pie charts show the frequency distribution of

Answers:

a. one variable.

b. two variables.

c. three or more variables.

d. Any of the above

Question 22

The homicide rate for a city is reported as 23.89. This means that

Answers:

a. For every 100,000 people in the population there were 23.89 homicides.

b. for every homicide, there were 23.89 victims.

c. There was an average of 23.89 homicides each month.

d. The homicide rate is rising.

Question 23?The purpose of univariate descriptive statistics is to

Answers:

a. ?combine nominal and discrete variables.

b. ?summarize relationships between many variables.

c. ?display the essential meaning of variables measured at the interval-ratio level.

d. ?summarize a single variable.

Question 24When working with a very small number of cases, it is usually preferable to report

Answers:

a. fractions.

b. actual frequencies.

c. percentages.

d. proportions.

Question 25Which of the following is an impossible value for a percentage?

Answers:

a. 0.0%

b. 0.05%

c. 47.458923%

d. 110.00%