Business Stats- Chapter 1

The number of observations in a complete data set having 20 elements and 3 variables is

The number of elements is equal to the number of observations. There are 20 elements, therefore 20 observations.

The collection of all elements of interest in a particular study is

The population of interest. The collection of all elements of interest in a particular study is the population of interest. The population of interest is the entire collection of elements being examined in a particular study. See Section 1.4, Descriptive Statistics.

A time series is a sequence of data points, typically consisting of successive measurements made over a time interval. Examples of a time series analysis include all except

The volume of shares traded today in the stock market

The American Statistical Association describes eight general topic areas and specify important ethical considerations under each topic. One area is "Professionalism". Professionalism points out the need for competence, judgment, diligence, self-respect, and worthiness of the respect of other people. Which of the following adhere to upholding the ethical guidelines for statistical practice?

Use only statistical methodologies suitable to the data and to obtaining valid results. For example, address the multiple potentially confounding factors in observational studies and use due caution in drawing causal inferences. b. Guard against the possibility that a predisposition (bias) by investigators or data providers might predetermine the analytic result. c. Account for all data considered in a study and explain the sample(s) actually used. d. All these are valid elements of professionalism and maintaining ethical guidelines. Correct. All of these are valid elements of professionalism found on their website. See Section 1.9 and

All of the following are examples of observational studies except

the behavior of Walmart shoppers after they are given a $20 gift card from the store.

In a random sample of 200 items, 5 items were defective. An estimate of the percentage of defective items in the population is

2.5%. Correct. An estimate of the percentage of defective items in the population is 2.5%. The proportion of defective items in the sample is a good estimator for the proportion of defective items in the population. 5/200 =0 .025. See Section 1.5, Statistical Inference.

An experiment is conducted that wishes to study the effects of a new blood pressure medicine on subjects. A random sample of 60 people are placed into three groups of 20 according to their age (young, middle-aged, senior). Each group of twenty people are randomly assigned to two treatment groups, new medicine and placebo. How many total treatment groups are there?

6-Correct. Three age groups x two treatments = 6 treatment groups. See Section 1.3, Data Sources.

Examples of categorical data include all of the following except

90210 (Beverly Hills). b. extra large. c. blonde. d. 228 lbs. - Correct Weight measured in pounds is a continuous, numerical piece of data, therefore quantitative.

What is the principal connection between a sample and a population

A random sample drawn from a population seeks to describe the characteristics of that population

What is the principal connection between a sample and a population?

A random sample drawn from a population seeks to describe the characteristics of that population.

What is the principal difference between time series data and cross sectional data?

Cross-sectional data are limited to an approximate window of time, while time series collects data over several time periods. Correct. Cross-sectional data are limited to an approximate window of time, while time series collects data over several time periods.

The Department of Transportation of a city has noted that on the average there are 17 accidents per day. The average number of accidents is an example of

Descriptive statistic. The Department of Transportation of a city has noted that on the average there are 17 accidents per day. The average number of accidents is an example of a statistic. See Section 1.4, Descriptive Statistics.

The largest experimental statistical study ever conducted is believed to be for​

Polio. Correct. The largest experimental statistical study ever conducted is believed to be the 1954 Public Health Service experiment for the Salk polio vaccine. Nearly 2 million children in grades 1, 2, and 3 were selected from throughout the United States

All of these terms are types of data acquisition errors except

a particularly extreme value is verified, yet still included in the data set

All of these terms are types of data acquisition errors except

a particularly extreme value is verified, yet still included in the data set. All of these terms are types of data acquisition errors except a particularly extreme value is verified, yet still included in the data set. Although the data is an outlier it should not be and is not ignored because it is properly verified

In a sample of 1,600 registered voters, 912, or 57%, approve of the way the President is doing his job. The 57% approval rating is

a. descriptive statistic

In a sample of 1,600 registered voters, 912, or 57%, approve of the way the President is doing his job. The 57% approval rating is an example of

a. descriptive statistic. The 57% approval rating is a statistic

Many data analysts define big data by referring to the three V's of data, which include all of the following except

a. variety. b. volume. c. velocity. d. validity. Correct. Validity is not one of the three main "V's". Many data analysts define big data by referring to the three V's of data: volume, velocity, and variety

A company wants to enhance benefits for their yearly healthcare package offering. They observe the set of employees who smoke on their break times at 10am, 12pm, and 2pm. They record the number of cigarettes smoked by each individual. This is an example of

an observational study. This is an example of an observational study. Studies of smokers and nonsmokers are observational studies because researchers do not determine or control who will smoke and who will not smoke. See Section 1.3, Data Sources

Data obtained from a nominal scale

can be either numeric or nonnumeric.

Examples of cross-sectional data include all but one of the following scenarios

compare the sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter.

Examples of cross-sectional data include all but one of the following scenarios

compare the sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter. Correct. An example that is not classified as cross sectional data would be the scenario to compare the sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter. The sales data is examined over a 3-month time interval

Data visualization is an analytical technique that falls in the

descriptive analytics

Data dashboard is an analytical technique that falls in the category of

descriptive analytics. A data dashboard is an analytical technique that falls in the category of descriptive analytics. Descriptive analytics encompasses the set of analytical techniques that describes what has happened in the past

Data dashboard is an analytical technique that falls in the category of

descriptive analytics. A data dashboard is an analytical technique that falls in the category of descriptive analytics. Descriptive analytics encompasses the set of analytical techniques that describes what has happened in the past.

Simulation, which is the use of probability and statistical computer models to better understand risk, falls under the category of

descriptive analytics. Simulation, which is the use of probability and statistical computer models to better understand risk, falls under the category of descriptive analytics. Descriptive analytics encompasses the set of analytical techniques that describes what has happened in the past

The owner of a factory regularly requests a graphical summary of all employees' salaries. The graphical summary of salaries is an example of

descriptive statistics.

The Department of Homeland Security has noted that on average 1120 suspicious vehicles are stopped and searched each day in the United States. This number is used to estimate the number of cars stopped in an average yearly period. The average number of cars stopped is not an example of

descriptive statistics. The average number of cars stopped is an example of a descriptive statistic. The statistic mentioned is gathered daily and used to describe the population of the United States. See Section 1.5, Statistical Inference.

The owner of a factory regularly requests a graphical summary of all employees' salaries. The graphical summary of salaries is

descriptive statistics. The graphical summary of salaries is an example of is an example descriptive statistics

The summaries of data, which may be tabular, graphical, or numerical, are referred to as

descriptive statistics. The summaries of data, which may be tabular, graphical, or numerical, are referred to as descriptive statistics. This set of analytical techniques is used to define and describe statistical data. See Section 1.4, Descriptive Statistics.

Analytics is generally thought to comprise three broad categories of techniques that include all of the following except

diagnostic analytics. Analytics is generally thought to comprise three broad categories of techniques that include prescriptive, descriptive, and predictive analytics. Diagnostic analytics is not a type of statistical analytic process.

The entities on which data are collected are

elements.

The sample size

is always smaller than the population size.

Data collected through a survey attached to this month's paystub

is considered an observational study because no control is imposed. Data collected through a survey attached to this month's paystub is considered an observational study because no control is imposed. Management just wants a response from the employee and communicates in the most convenient way.

Statistical Inference

is the process of drawing conclusions about the population based on the evidence taken from the sample. Statistical inference is the process of drawing conclusions about the population based on the evidence taken from the sample

Statistical studies in which researchers do not control variables of interest are

observational studies. Statistical studies in which researchers do not control variables of interest are observational studies. An observational study simply gathers information on phenomena without imposing any control over the elements being observed.

Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example

ordinal scale. . Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of the ordinal scale. Ordinal data is data in which the order or rank is meaningful.

Optimization models, which generate solutions that maximize or minimize some objective subject to a set of constraints fall into the category of

prescriptive analytics.

The set of analytical techniques that yield a best course of action

prescriptive analytics.

Data mining deals with methods for developing useful decision making information from large databases. It performs all actions except

reselling the packaged data. Data mining includes collection, extraction, warehousing, and analysis of predictive information. See Section 1.7, Big Data and Data Mining.

The major applications of data mining have been made by companies with a strong _______ focus.

retail/consumer. The major applications of data mining have been made by companies with a strong consumer focus, such as retail businesses, financial organizations, and communications companies. See

In a sample of 200 students in a university, 40, or 20%, are Communications majors. Based on the above information, the school's paper reported that "an estimated 20% of all the students at the university are Communications majors." This report is an example of

statistical inference. This university report is an example of statistical inference. The report uses a statistic to describe a characteristic of a population

Data mining is the analysis step of the "knowledge discovery in databases" process. It has become an emerging field in today's business world because

the sheer amount of useful data has grown exponentially.

Which variable would be continuous and quantitative?

the time it takes to grill a steak.The time it takes to grill a steak is a continuous and quantitative variable. The time it takes can be measured. See Section 1.2, Data.

Anyone wanting to use data and statistical analysis as aids in decision making must be aware of time and cost issues. If important data are not readily available, it would be best to

use a cross-sectional data set. If important data are not readily available, it would be best to use a cross-sectional data set. This option allows for data to be taken in a short time window. This would also be best in terms of cost. It would also be advantageous because existing data could be used

Examples of quantitative data include all of the following except

your zip code. Examples of quantitative data include all of the following except your zip code. Although zip code is a number per set, it describes a location and can be viewed as categorical.