ISDS 2000

An analyst assigns a sample of bond issues to one of the following credit ratings, given in descending order of credit quality (increasing probability of default): AAA, AA, BBB, BB, CC, D.

ordinal

Rating products from one to five stars generates ___________ data.

ordinal

the restaurant surveys its customers about the quality of its waiting staff on a scale of 1 to 4, where 1 is poor and 4 is excellent.

ordinal

When creating a bar chart or a histogram, each bar/rectangle should be of the _____________ width.

same

Sampling, rather than surveying an entire population, can offer some substantial benefits. Some of those benefits include

saving money and time

Data that are collected by recording a characteristic of a subject over several time periods are referred to as ______ data.

time series

An ogive is a graph that plots the cumulative frequency, or cumulative relative frequency, against the

upper limit of the corresponding class.

Scale of Measurement: Nominal

uses tags or labels to associate value with the rank; differentiates items based on the categories they belong to

Which characteristic of big data does the following describe? Organizations must develop a methodical plan for formulating business questions, curating the right data, and unlocking the hidden potential in big data.

value

Data that are collected about many subjects at the same point in time or without regard to differences in time are known as ______ data.

cross-sectional

A _______________ _________________ distribution shows the number of observations that fall below the upper limit of a particular interval.

cumulative frequency

When a researcher examines quantitative data and wants to know the number of observations that fall below the upper limit of a particular class, the researcher is BEST served by creating a ______.

cumulative frequency distribution

Scale of Measurement: Ordinal

depicts the order/rank of variables and not the difference between them; measures quality

The branch of statistics that summarizes important aspects of a data set is often referred to as ______ statistics.

descriptive

Two branches of the study of statistics:

descriptive and inferential

Consider the following variable: the number of people in a household. This variable is best categorized as a ______ variable.

discrete

In general, data are compilations of

facts, figures, or other contents

A ______ is a way to organize qualitative data into categories and record the number of observations in each category.

frequency distribution

In order to summarize qualitative data, a useful tool is a(n) ______.

frequency distribution

In descriptive statistics, a polygon is best described as a

graph that connects the midpoints of each class and its associated frequency or relative frequency.

A stem-and-leaf diagram has two parts: The stem and the leaf. The stem consists of the ______ and the leaf consists of the ______.

leftmost digits; last digit

Scale of Measurement: Interval

measured on specific numerical values and there are equal distances between attributes; intervals are always equal

The dean of the business school at a local university categorizes students by major (i.e., accounting, finance, marketing, etc.) to help in determining class offerings in the future.

nominal

kindergarten teacher marks if a student is a girl or a boy

nominal

Key word for cross-sectional data

now or current

population parameter

number that describes something about an entire group or population

A cumulative frequency distribution identifies the number of ___________________ that falls below the upper limit of a particular interval.

observations

In general, we use sample data because

obtaining data from the population is often an expensive process

In order to approximate the class width for a frequency distribution of quantitative data, we calculate:

(Largest value−Smallest value)/Number of classes

_____________ data can include hourly, daily, weekly, monthly, quarterly, or annual observations.

Time series

Many experts believe that _____ of the data in the world today were created in the last two years alone.

90%

How does an ogive differ from a polygon?

An ogive is a graph of a cumulative (relative) frequency distribution, while a polygon is a graph of a (relative) frequency distribution.

Numerical Variable

Have values that describe a measurable quantity as a number

Continuous v. Discrete

Discrete data is counted while continuous data can take any value in a range

Difference between descriptive and inferential statistics

Inferential applies to ALL of a population while descriptive uses a sample (key word for inferential is ALL)

With data that is measured on this scale, we are able to categorize and rank the data as well as find meaningful differences between observations.

Interval scale

Rank order these measurement scales from weakest to strongest.

Nominal -> Ordinal -> Interval -> Ratio

This represents the least sophisticated level of measurement.

Nominal scale

Interval

Observations can be categorized and ranked, and differences between observations are meaningful.

Ordinal

Observations can be categorized and ranked; however, differences between the ranked observations are meaningless.

Nominal

Observations differ merely by name or label

Ratio

Observations have all the characteristics of interval-scaled data as well as a true zero point.

Cross-sectional data has to do with

One point in time

With this data, we are only able to both categorize and rank the data with respect to some characteristic or trait.

Ordinal scale

When constructing a histogram, what values/labels go on the horizontal (x) axis and the vertical (y) axes?

Quantitative class limits on the horizontal axis; frequency or relative frequency on the vertical axis.

A _____ variable is characterized by uncountable values within an interval.

continuous

_____ data often consist of numerical information that is objective and is not open to interpretation.

Structured

Categorical Variable

Take on values that are names or labels

Relative Frequency Distribution Formula

Total number of items, and then divide the frequency count by the total number

This type of data does not conform to a predefined, row-column format.

Unstructured

Which characteristic of big data does the following describe? Data from a variety of sources get generated at a rapid speed.

Velocity

The interval scale of measurement

allows for the use of negative values

The main drawback of interval-scaled data is that the value of zero is __________ chosen.

arbitrarily

A qualitative variable is also known as a ________ variable.

categorical

Relative frequency distributions are generally more useful than frequency distributions when

comparing data sets of different sizes.

The branch of statistics that draws conclusions about a large set of data based on a smaller set of data is often referred to as ______ statistics.

inferential

It is important to note that numerical results are not very useful unless they are accompanied with clearly stated actionable business

insights

a ski resort records the daily temperature during the month of January

interval

a sociologist notes the birth year of 50 individuals

interval

One method of graphical presentation for qualitative data is a(n) ______.

pie chart

A ______________ includes all items of interest in a statistical problem

population

Inferential statistics refers to drawing conclusions about a large set of data, called a ___________, based on a smaller set of data called a __________.

population, sample

Scale of Measurement: Ratio

produces the order of variables and makes the difference between variables known; can have zeros which means the variable can be not present

A meteorologist records the amount of monthly rainfall over the past year.

ratio

A research analyst collects data on the weekly closing price of gold throughout the year. The scale for these data is ______.

ratio

An investor collects data on the weekly closing price of gold throughout a year.

ratio

An investor monitors the daily stock price of BP following the 2010 oil disaster in the Gulf of Mexico.

ratio

This scale has all the characteristics of the interval scale as well as a true zero point, which allows us to interpret the ratios between observations.

ratio scale

In a given cumulative frequency distribution, the "cumulative frequency" column value for the third class represents

the sum of observations in the first, second and third classes.