Deck 2: Basic Descriptive Statistics Percentages, Ratios Rates, Tables, Charts Graphs

Question 1

The midpoints of intervals for frequency distributions constructed with interval-ratio variables are found by

A) adding the upper and lower class limits for each interval and then dividing by 2.
B) multiplying the upper and lower class limits for each interval
C) dividing the range by 10
D) None of the above. Class intervals for interval-ratio variables do not have midpoints.

Answer 1

adding the upper and lower class limits for each interval and then dividing by 2.

Question 2

A possible problem with Table 1 is that

A) class intervals overlap
B) class intervals are too large
C) class intervals are unequal in size
D) class intervals are exhaustive

Answer 2

class intervals are unequal in size

Question 3

Cumulative frequencies and cumulative percentages allow a researcher to

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

Answer 3

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

Question 4

When constructing frequency distributions for variables measured at the interval-ratio level, approximate interval size (or interval width) can be found by

A) dividing sample size (N) by 10
B) multiplying the number of categories by the lowest score
C) dividing the range by the sample size (N)
D) dividing the range (R) by the number of categories (k)

Question 5

In Table 1, what proportion of cases are 18-23?

A) 0.05
B) 0.36
C) 0.78
D) 0.13

Question 6

Forty of every two hundred students attend all of their classes. What percentage of the student body is this?

A) 5%
B) 50%
C) 2%
D) 20%

Question 7

In Table 1, what percentage of cases is in the 18-23 age group?

A) ( 5/36) x 100 = 13.51%
B) (18/23) x 100 = 78.26%
C) (36/ 5) x 100 = 7.4%
D) ( 5/21) x 100 = 23.81%

Question 8

If we added a cumulative percentage column to Table 1 and began our calculations with the 18-23 interval, the entry in the 30-40 interval would be

A) 10%
B) 33.3%
C) 37%
D) 100%

Question 9

The class intervals below represent ages of young adult respondents. Which set of intervals is both exhaustive and mutually exclusive?

A) 18-19 19-20
20-21
B) 18-19 20-21
22-23
C) 18-20 22-24
26-28
D) 18-19 21-22
24-25

Question 10

If 60 cases range in score from 4 to 84 and you want 10 intervals in a frequency distribution, approximately what will be the width of each interval?

A) 4
B) 8
C) 12
D) 60

Question 11

As a very general rule, frequency distributions should have ___ categories.

A) less than 5
B) more than 20
C) no more than 5
D) about 10

Question 12

Twenty-three of the 50 states rejected a proposed constitutional amendment to make the house fly the National Insect. What percentage is this?

A) 23%
B) 25%
C) 46%
D) 54%

Question 13

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

A) 0.0%
B) 47.458923%
C) 110.00%
D) 0.05%

Question 14

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

A) nominal
B) ordinal
C) interval-ratio
D) all of the above

Question 15

To calculate a proportion, the number of cases in any category (f) is divided by

A) the total number of categories (k)
B) the number of cases in all categories (N)
C) the cases in that category (f)
D) the number of cases in adjacent categories (k-1)

Question 16

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

A) percentages
B) proportions
C) fractions
D) actual frequencies

Question 17

The sum of the proportions for all categories of a variable will be

A) 100.00
B) 10.00
C) 1.00
D) 0.10

Question 18

In Table 1, what is the ratio of 30-40 year olds to 18-23 year olds?

A) 0.24:1.00
B) 4.20:1.00
C) 2.00:1.00
D) 1.00:1.00

Question 19

To be converted to a percentage, the proportion must be multiplied by

A) 10
B) 100
C) 1000
D) any of the above

Question 20

A frequency distribution should reflect a balance of

A) detail and conciseness
B) time and money
C) questions and answers
D) elegance and symmetry

Question 21

Open-ended intervals

A) are always preferable to unequal intervals
B) should never be used in actual research
C) can be useful when there are a few very high or very low scores in a distribution
D) should only be used with ordinal-level variables

Question 22

To find the ratio of smokers to non-smokers, you would

A) divide the number of non-smokers by the number of smokers
B) add them together and divide by the number of smokers
C) divide the number of smokers by the number of non-smokers
D) multiply the number of smokers by the total number of people

Question 23

In reading SPSS output for the Frequencies procedure, we usually ignore the 'Percent' column because it

A) includes "missing" scores
B) excludes scores labeled DK and NA
C) is appropriate only for nominal-level variables
D) is based on cumulative percentages

Question 24

Proportions and percentages, ratios and rates are all ways of expressing

A) concise distributions of a variable
B) data without leaving out any details
C) relative frequencies
D) raw frequencies

Question 25

In Table 2, which is the correct fraction for determining the proportion of Independents in community B?

A) 15/17
B) 15/264
C) 64/15
D) 15/64

Question 26

A class has 20 men and 10 women. The ratio of women to men is

A) 2 to 1
B) 1 to 2
C) 20%
D) .2

Question 27

The crude birth rate of a city that has 250 births in a year and a population of 7500 would be found by using which of the following?

A) crude birth rate = (250/7500) x 1000
B) crude birth rate = 7500/250
C) crude birth rate = (1000/7500) x 250
D) crude birth rate = (250/1000) x 7500

Question 28

In Table 2, which community has the higher proportion of Independents?

A) Community A
B) Community B
C) Neither
D) This proportion can't be determined from the information given.

Question 29

A possible problem with open-ended or unequal intervals is that they

A) do not permit the computation of midpoints
B) are useful only for nominal-level variables
C) can be used only with variables that have few scores
D) cannot be used for interval-ratio level variables

Question 30

The ratio of men to women in a karate class is 3.3:1. If there are 100 women, how many men are there?

A) 33
B) 66
C) 133
D) 330

Question 31

City A (population = 1567 people) had 34 auto thefts last year. City B (population = 34,567) had 40 auto thefts in the same time period and City C (population = 156,980) had 70 auto thefts. Which city had the highest RATE of auto theft?

A) City A
B) City B
C) City C
D) More information is needed to answer this question.

Question 32

According to the text book, the rate of traffic fatalities in the United States

A) fell between 1994 and 2011
B) rose dramatically between 1994 and 2011
C) rose between 1980 and 2000 and then fell
D) fell between 1980 and 2000 and then rose

Question 33

In Table 2, what percentage of Community A are Republicans?

A) (103/264) x 100 = 39.02
B) (103/17) x 100 = 605.88
C) (264/328) x 100 = 80.49
D) (103/135) x 100 = 76.30

Question 34

A small town of 1,709 residents had one homicide in the past year. The homicide rate for this town

A) cannot be determined from the information given
B) is (1/1709) x 100,000
C) is rising
D) is (1709:1) x 1,000

Question 35

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

A) for every homicide, there were 23.89 victims
B) For every 100,000 people in the population there were 23.89 homicides
C) The homicide rate is rising
D) There was an average of 23.89 homicides each month

Question 36

A 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

A) double the number 10 years ago
B) actually about the same as 10 years ago
C) equal to the number 10 years ago plus 50%
D) triple the number 10 years ago

Question 37

In Table 2, what is the ratio of Independents to Socialists in Community A?

A) 15:11
B) 17:9
C) 9:17
D) 17:264

Question 38

In Table 2, what is the ratio of Socialists to Democrats in Community B?

A) 11:21
B) 11:64
C) 64:11
D) 9:11

Question 39

A city of 1567 people had 34 auto thefts last year. The auto theft rate for this city

A) cannot be determined from the information given
B) is falling
C) is (34/1567) x 100,000
D) is (100,000 x 1567)/34

Question 40

In Table 2, what percentage of Democrats lives in community B?

A) (21 / 64) x 100 = 32.8
B) (21/328) x 100 = 6.4
C) (21/156) x 100 = 13.5
D) (64/264) x 100 = 24.2

Question 41

According to the report discussed in the text, about what percentage of high school students have used cigarettes, alcohol, marijuana, or cocaine at least once?

A) 100%
B) 75%
C) 25%
D) 10%

Question 42

A researcher wants to visually display the U.S. divorce rate (an interval-ratio level variable) for the last 50 years. An appropriate format would be

A) a line chart or histogram
B) only a histogram would work in this situation
C) a pie chart
D) none of the above. Data in the form of rate should never be displayed in a chart or graph.

Question 43

Pie charts show the frequency distribution of

A) one variable
B) two variables
C) three or more variables
D) any of the above

Question 44

For a single variable at the interval-ratio level, an appropriate graph would be

A) a pie chart
B) a histogram
C) a bivariate table
D) none of the above. Graphs are never used for interval-ratio level variables

Question 45

A line chart or frequency polygon is based on

A) the upper limits of each interval
B) the lower limits of each interval
C) the midpoint of each interval
D) any limit which the researcher selects

Question 46

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

A) nominal level
B) ordinal level
C) interval-ratio level
D) any level

Question 47

According to information presented in the text, the US divorce rate

A) has generally fallen since the early 1980s
B) has been rising steadily since the 1950s
C) has been basically unchangedsince the 1970s
D) rose until the 1990s and then began to fall sharply

Question 48

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

A) pie chart
B) histogram
C) frequency polygon
D) bivariate table