ECO 351 Test One

In a study, the categories for the Quality are Good, Very Good, and Excellent, whereas the categories for the Price are High, Moderate, and Low. What is the number of cells appearing in the crosstabulation?

9

What technique can be used to compare the relative frequency of two categorical variables?

Stacked Bar Chart

Which of the following statements regarding the sampling distribution of sample means is incorrect?

The standard deviation of the sampling distribution is the standard deviation of the population.

Examples of ratio scale include all of the following except: the duration in minutes of daily dog walking. the dog's height. the dog's gender. the dog's weight.

gender

The sample size: is always equal to the population size. is always smaller than the population size. can be larger than the population size. can be larger or smaller than the population size.

is always smaller than the population size.

A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 80 and 12, respectively. The standard error of the mean is:

1.2

A simple random sample of 64 observations was taken from a large population. The sample mean and standard deviation were determined to be 320 and 120, respectively. The standard error of the mean is:

15

In a random sample of 200 items, 5 items were defective. An estimate of the percentage of defective items in the population is: 20.0%. 5.0%. 2.5%. 10.0%.

2.5

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

20

Examples of categorical data include all of the following except: 228 lbs. extra large. blonde. 90,210 (Beverly Hills).

228 lbs

For the data involving the ACT exam score of the sample of 100 students, the largest data value is 32, and the smallest data value is 17. If we decided to summarize the data with five classes, what is an approximate class width?

3

An experiment is conducted 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, and senior). Each group of 20 people are randomly assigned to two treatment groups (new medicine and placebo). How many total treatment groups are there?

6

What is the principal connection between a sample and a population? Small samples can be drawn to describe small populations. A random sample drawn from a population seeks to describe the characteristics of that population. A population describes all sample data. A population cannot be accurately described by any sample.

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

What graphical summary can be used for the data showing the number of nations with the amount of national debt to GDP (less than 40%, between 40% and 80%, more than 80%)? A histogram Neither a bar chart nor a histogram Both a bar chart and a histogram A bar chart

bar chart

Data obtained from a nominal scale: must be numeric. can be either numeric or nonnumeric. must be alphabetic. must rank and order the data.

can be either numeric or nonnumeric.

The process of conducting a survey to collect data for the entire population is called: an experiment statistical inference. a sample survey. a census.

census

What is the principal difference between time series data and cross-sectional data? Time series data and cross-sectional data are concerned with different sized samples. Time series data seeks only to capture data within a snapshot in time. Cross-sectional data looks at only a particular "cross-section" of the population. Cross-sectional data are limited to an approximate window of time, while time series data are collected over several time periods.

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

The Department of Health and Human Services of a city has noted that, on average, there are 48 newborns per day. The average number of newborns is an example of:

descriptive stat

Data collected through a survey attached to this month's pay stub: will be useless because not everyone receives the survey. is considered an observational study because no control is imposed. is experimental because the control is the time of month it was administered. will have no data acquisition error.

is considered an observational study because no control is imposed.

A student asked classmates how tall they are, in which month they were born, and whether they are in a relationship. How many of these variables are quantitative and how many of these variables are categorical?

One is quantitative. Two are categorical.

Which of the following would likely display a negative relationship when creating a scatter diagram?

The number of classes a student misses during a semester and the grade obtained in the course

The National museum collects data on its visitors for a year. What is the population being studied? The population is all visitors coming to the museum on weekends. The population is all visitors coming with children to the museum. The population is all visitors coming to the museum. The population is all females coming to the museum.

The population is all visitors coming to the museum.

Numerical values that indicate how much or how many are known as

quantitative data.

What is open-source software for performing data mining? Both R and Python Python R Neither R nor Python

r and python

Doubling the size of the sample will:

reduce standard error of mean

In a recent Gallup Poll, the decision was made to increase the size of its random sample of voters from 1500 people to about 4000 people. The purpose of this increase is to:

reduce the standard error of the estimate.

Data mining deals with methods for developing useful decision-making information from large databases. It performs all actions except the: reselling of the packaged data. collection of useful data. extraction of predictive information. warehousing of data.

reselling of packaged data

A graphical presentation of the relationship between two quantitative variables is called a:

scatter diagram.

A graphical display for depicting multiple bar charts on the same display is called a:

side by side

A display used to compare the frequency, relative frequency, or percent frequency of two categorical variables is a:

stacked

Which of the following graphical displays should not be used for quantitative data?

stacked bar

The standard deviation of a point estimator is called the:

standard error.

In a sample of 750 citizens, 405, or 54%, support a new city's tax law. Based on the above information, the study reported that "an estimated 54% of all the citizens support a new city's tax law." This report is an example of: an experiment. a population. a sample. statistical inference.

statistical inference

A polling organization asks whether you are satisfied with your standard of living. Among 1500 residents of the capital, only 44% are completely satisfied. The 44% satisfaction rating is an example of: a population. descriptive statistics. a sample. statistical inference.

descriptive stats

The central limit theorem is important in statistics because it:

enables reasonably accurate probabilities to be determined for events involving the sample average when the sample size is large regardless of the distribution of the variable

The central limit theorem states that:

if the sample size n is large, then the sampling distribution of the sample mean can be approximated by a normal distribution.

The proper way to construct a stem-and-leaf display for the data set {51, 55, 58, 73, 73, 76, 92, 94, 95, and 97} is to:

include stems labeled "6" and "8" and enter no leaves on these stems.

An approximate value of a population parameter that provides limits and believed to contain the value of the parameter is known as the:

interval estimate.

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 an example of: statistical inference. a sample. descriptive statistics. a population.

statistical inference

Examples of cross-sectional data include all of the following except: the comparison of five different variables for the 60 World Trade Organization nations on January 1st. the comparison of performance of all telecommunications stocks today. the comparison of sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter. the comparison of mpg data gathered in a study on all 2015 cross-over SUVs.

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

A cumulative relative frequency distribution shows:

the proportion of data items with values less than or equal to the upper limit of each class.

histogram is

a graphical presentation of a frequency or relative frequency distribution.

25 students received grades A, B, and C for their essay: 8 A, 11 B, and 6 C. Determine the relative frequency of grade A.

.32

In a cumulative relative frequency distribution, the last class will have a cumulative relative frequency equal to:

1

The American Statistical Association describes eight general topic areas and specifies important ethical considerations under each topic. One area is "Responsibilities to Research Subjects." It describes the requirements for protecting the interests of human and animal subjects of research not only during data collection but also in the analysis, interpretation, and publication of results of the findings. Which of the following is not an example of this? Avoiding or minimizing the use of deception Avoiding excessive risk to research subjects and excessive imposition on their time and privacy Knowing about and adhering to appropriate animal welfare guidelines in research involving animals Assuming legal privacy and confidentiality protections where they may not apply

Assuming legal privacy and confidentiality protections where they may not apply

he American Statistical Association describes eight general topic areas and specifies 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 does not 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. Guard against the possibility that a predisposition (bias) by investigators or data providers might predetermine the analytic result. Account for all data considered in a study and explain the sample(s) actually used. Engage in discrimination based on personal characteristics.

Discrimination

Which of the following is not a recommended guideline for creating an effective graphical display?

Use three dimensions whenever possible to give the display depth.

A frequency distribution is a tabular summary of data showing the:

number of observations in several classes.

All of the following are examples of observational studies except: a Gallup poll measuring the approval rating of the president. an online survey to record your satisfaction with a company's service. the number of cars running a stop sign in a residential area during rush hour. the behavior of Walmart shoppers after they are given a $20 gift card from the store.

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

Which of the following is an example of an observational study? The researchers examined how often people, depending on their age, use social media per day. 120 adults were randomly divided into three equal groups. The first group was told to drink coffee, the second group was told to drink tea, and the third group was told to drink a glass of water before sleeping for a month. Researchers then compared when each group fell asleep. One group of patients receive a new treatment, while another group is given a traditional treatment. Then the efficacy of the new treatment in comparison with the traditional one is studied. 700 unemployed were randomly divided into two groups. One group was given unemployment compensation of $2,000 per month, while the other received only $1,000. Then researchers analyzed how many days unemployed in each group spent to find a job.

The researchers examined how often people, depending on their age, use social media per day.

Which of the following is used for data-driven decision making? descriptive statistics analytics statistical inference time series data

analytics

A set of visual displays that organizes and presents information that is used to monitor the performance of a company or organization in a manner that is easy to read, understand, and interpret is called a:

data dashboard.

A company wants to enhance the benefits for its yearly healthcare package offering. It observes the set of employees who smoke on their break times at 10 a.m., 12 p.m., and 2 p.m. It records the number of cigarettes smoked by each individual. This is an example of: an observational study. a randomized study. a controlled experiment. a study using existing sources.

observational study

A sample of 92 observations is taken from an infinite population. The sampling distribution of is approximately normal because

of CLT

Question Content Area Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of the: ratio scale. ordinal scale. interval scale. nominal scale.

ordinal scale

Which of the following is not a type of data acquisition errors? A particularly extreme value is verified, and is still included in the data set. A subject's answers may be transcribed incorrectly. The person asking a survey question may place undo emphasis on one of the answer choices. Data being used before the source is properly vetted.

particularly extreme value is verified, and is still included in the data set.

The largest experimental statistical study ever conducted is believed to be for:​ diphtheria. cholera. polio. flu vaccine.

polio

A group of employees at a major grocery chain is tasked with analyzing point of sale data to predict the success of a marketing campaign they are considering launching. This is an example of: prescriptive analysis. descriptive statistics. descriptive analysis. predictive analysis.

predictive analysis.

In data mining, statistical models play an important role in developing _____. financial organizations predictive models human resources businesses

predictive models

A time series is a sequence of data points, typically consisting of successive measurements made over a time interval. Examples of the time series include all of the following except: point differential against opponents for a football team this year. a stock's opening price for each month. ocean tides. A time series is a sequence of data points, typically consisting of successive measurements made over a time interval. Examples of the time series include all of the following except: point differential against opponents for a football team this year. a stock's opening price for each month. ocean tides. the volume of shares traded today in the stock market.

the volume of shares traded today in the stock market.

Which of these is a continuous and quantitative variable? The number of internet sales on Cyber Monday The pairs of shoes in your closet The number keys on a piano The time it takes to grill a steak

time it takes to grill a steak

anyone who wants to use the data and statistical analysis as aids to decision making must be aware of the time and cost issues. If important data are not readily available, it would be best to: do nothing at all due to cost. use a cross-sectional data set. conduct a times series analysis. borrow another company's data.

use a cross-sectional data set.

Big data is often defined according to the four v's of data: volume, variety, veracity, and ___________. visibility vacancy velocity validity

velocity

The main difference between prescriptive analysis and descriptive/predictive analysis is that prescriptive analysis: yields a course of action. describes what has happened in the past. uses past data to predict the future. uses linear regression and time series analysis.

yields course of action

Examples of quantitative data include all of the following except: the number of pairs of shoes in your closet. your weight rounded to the nearest gram. the temperature outside to the nearest degree. your zip code.

zip code