12.5 is an example of statistical inference.

TRUE/FALSE

• A variable is a characteristic that changes or varies over time, and/or for different individuals

or objects under consideration. An experimental unit is the individual or object on which a variable is measured.

ANS: T PTS: 1

• Bar and pie charts are graphical techniques for qualitative data. The former focus the attention

on the frequency of the occurrences of the categories, and the later emphasize the percentage of occurrences of each category.

ANS: T PTS: 1

• In a sample of 1000 students in a university, 125 of them or 12.5% are biology majors. The

12.5% is an example of statistical inference.

ANS: F PTS: 1

• Individual observations within each class may be found in a frequency distribution.

ANS: F PTS: 1

• Twenty-five percent of a sample of 200 professional tennis players indicated that their parents

did not play tennis. This is an example of descriptive statistics as opposed to inferential statistics.

ANS: T PTS: 1

• A local cable system using a sample of 1000 subscribers estimates that fifty percent of its

subscribers watch premium channel at least five times per week. This is an example of inferential statistics as opposed to descriptive statistics.

ANS: T PTS: 1

• Statistical inference is the process of making an estimate, prediction, or decision about a

population based on sample data.

ANS: T PTS: 1

• In the term "frequency distribution," frequency refers to the number of data values or

measurements falling within each class.

ANS: T PTS: 1

• A branch of the statistics discipline that is used to develop and utilize techniques for

effectively presenting numerical information is called inferential statistics.

(Introduction to Probability and Statistics 14e Mendenhall Robert, Barbara Beaver) (Test Bank all Chapters) 1 / 4

ANS: F PTS: 1

• A branch of the statistics discipline that is used to develop and utilize techniques for properly

making inferences about population characteristics from information contained in a sample drawn from this population is called inferential statistics.

ANS: T PTS: 1

• Persons or objects that have characteristics of interest to statisticians are called variables.

ANS: F PTS: 1

• A qualitative variable about which observations can be made in only two categories is a

bivariate data set.

ANS: F PTS: 1

• A variable that is normally described in words rather than numerically is a qualitative

variable.

ANS: T PTS: 1

• A discrete quantitative variable is one that can assume values only at specific points on an

interval of values, with inevitable gaps between them.

ANS: T PTS: 1

• A continuous quantitative variable is one that can assume values at all points on an interval of

values, with no gaps between possible values.

ANS: T PTS: 1

• Persons or objects on which an experiment is performed are called experimental units.

ANS: T PTS: 1

• Groupings of data, created to enhance an understanding of them, usually by making the

groups collectively exhaustive and mutually exclusive are called classes or categories.

ANS: T PTS: 1

• A tabular summary of categorical data set showing the number of observations that fall into

each of several collectively exhaustive and mutually exclusive classes is called a bar chart.

ANS: F PTS: 1

• A relative frequency distribution is a tabular summary of a data set showing the proportions of

all observations that fall into each of several collectively exhaustive and mutually exclusive classes.

ANS: T PTS: 1 2 / 4

MULTIPLE CHOICE

1. Descriptive statistics deals with methods of:

• organizing data
• summarizing data
• presenting data in a convenient and informative way
• all of these
• only organizing and summarizing data

ANS: A PTS: 1

2. The relative frequency of a class is computed by:

• dividing the frequency of the class by the number of classes
• dividing the frequency of the class by the class width
• dividing the frequency of the class by the total number of observations in the data

set

• subtracting the lower limit of the class from the upper limit and multiplying the

difference by the number of classes

• adding the lower limit of the class to the upper limit and multiplying the sum by

the number of classes

ANS: C PTS: 1

• Which of the following is not the goal of descriptive statistics?

• summarizing data
• displaying aspects of the collected data
• reporting numerical findings
• estimating characteristics of the population based on a sample
• none of these

ANS: D PTS: 1

• You asked ten of your classmates about their weight. On the basis of this information, you

stated that the average weight of all students in your university or college is 158 pounds. This

is an example of:

• descriptive statistics
• statistical inference
• sample
• population
• sample and population

ANS: B PTS: 1

5. The best type of chart for comparing two sets of qualitative data is:

• a line chart 3 / 4

• a pie chart
• a histogram
• a bar chart
• all of these

ANS: D PTS: 1

6. The sum of the frequencies for all classes will always equal:

• the number of classes
• the class width
• the total number of observations in the data set
• one
• the average

ANS: C PTS: 1

7. The two graphical techniques we usually use to present qualitative data are:

• bar chart and histogram
• histogram and pie chart
• bar chart and pie chart
• line chart and stem and leaf plot
• bar chart and line chart

ANS: C PTS: 1

• Which of the following statements is true?

• Univariate data result when a single variable is measured on a single experimental

unit.

• Bivariate data result when less than two variables are measured on a single

experimental unit.

• Multivariate data result when more than two variables are measured.
• Both univariate data result when a single variable is measured on a single

experimental unit and multivariate data result when more than two variables are measured are true.

• Both bivariate data result when less than two variables are measured on a single

experimental unit and multivariate data result when more than two variables are measured are true.

ANS: D PTS: 1

9. Characteristics possessed by experimental units are called:

• data sets
• descriptive statistics
• internal data
• variables

ANS: D PTS: 1

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