Question 1

A statistics professor asked students in a class their ages.Based on this information, the professor states that the average age of students in the university is 21 years.This is an example of _____.

Accepted Answer

The professor is using the sample data from the class to make a generalization about the entire university, which is an example of statistical inference.

Question 2

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

Accepted Answer

The graphical summary of salaries is a way to display descriptive statistics, which provide information about the central tendency, variability, and distribution of the data. It does not involve any sample selection or hypothesis testing, so choices A, C, and D are not appropriate.

Question 3

Exhibit 1-1
In a recent study based upon an inspection of 200 homes in Daisy City, 120 were found to violate one or more city codes.
-Refer to Exhibit 1-1.The Daisy City study is an example of the use of a _____.

Accepted Answer

The study is based on an inspection of only 200 homes out of a larger population, making it a sample.

Question 4

Exhibit 1-1
In a recent study based upon an inspection of 200 homes in Daisy City, 120 were found to violate one or more city codes.
-Refer to Exhibit 1-1.The city manager released a statement that 60% of Daisy City's 3,000 homes are in violation of city codes.The manager's statement is an example of _____.

Accepted Answer

The city manager's statement is based on a sample of 200 homes, but is making an inference about the population of 3,000 homes. Therefore, it is an example of statistical inference.

Question 5

The average age in a sample of 90 students at City College is 20.From this sample, it can be concluded that the average age of all the students at City College _____.

Accepted Answer

Since the average age of the sample is 20, it is possible that the average age of the entire population is also 20. However, it is also possible that the average age of the entire population is either larger or smaller than 20. Therefore, the best choice is D, which states that the average age could be larger, smaller, or equal to 20.

Question 6

Exhibit 1-1
In a recent study based upon an inspection of 200 homes in Daisy City, 120 were found to violate one or more city codes.
-Refer to Exhibit 1-1.The manager's statement that 60% of Daisy City's 3,000 homes are in violation of city codes is _____.

Accepted Answer

The statement is based on a sample of 200 homes and is therefore an approximation. It cannot be confirmed as accurate without further data or analysis.

Question 7

Of 800 students in a university, 360, or 45%, live in the dormitories.The 800 is an example of _____.

Accepted Answer

The 800 refers to the entire group of students in the university, which is the population.

Question 8

Six hundred residents of a city are polled to obtain information on voting intentions in an upcoming city election.The 600 residents in this study is an example of a(n) _____.

Accepted Answer

The 600 residents in this study represent a sample, which is a smaller subset of a population (in this case, the entire population of the city). A census would involve collecting data from every member of the population, which is often impractical or impossible. An observation refers to the process of watching or recording something as it naturally occurs, and while the poll could be considered an observation, it is more specifically a method of data collection. Finally, the population refers to the entire group of individuals being studied.

Question 9

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

Accepted Answer

Descriptive statistics summarize the data using tabular, graphical, or numerical methods. Inferential statistics, on the other hand, involve making conclusions or predictions about a larger population based on a sample, and statistical inference refers to the process of making such conclusions or predictions. Report generation is a broad term that can refer to any process of creating a document or report, and is not specific to statistics.

Question 10

The Department of Transportation of a city has noted that on the average there are 14 accidents per day.The average number of accidents is an example of _____.

Accepted Answer

The average number of accidents is a descriptive statistic, which summarizes the data that has already been collected. Statistical inference involves making predictions or generalizations about a population based on sample data, which is not applicable in this scenario. The number of accidents is not a sample or a population, but rather a measurement of a certain variable in a specific location.

Question 11

The collection of all elements of interest in a study is _____.

Accepted Answer

The population refers to the entire group of individuals, objects, or events that we want to study and draw conclusions about in a statistical analysis.

Question 12

Exhibit 1-2
In a sample of 3,200 registered voters, 1,440, or 45%, approve of the way the president is doing his job.
-Refer to Exhibit 1-2.A political pollster states, "Forty five percent of all voters approve of the president." This statement is an example of _____.

Accepted Answer

The statement is an example of statistical inference because it uses data from a sample to make a generalization about the entire population of voters.

Question 13

In a sample of 800 students in a university, 160, or 20%, are Business majors.Based on the above information, the school's paper reported, "20% of all students at the university are Business majors." This report is an example of _____.

Accepted Answer

The report makes a generalization about the entire population of students at the university based on the sample data, which is an example of statistical inference.

Question 14

Statistical inference _____.

Accepted Answer

Statistical inference is the process of drawing conclusions about the population based on the information obtained from a sample. Descriptive statistics, on the other hand, is the process of summarizing and presenting the characteristics of a sample or population. A census is a method of collecting data from the entire population, while statistical inference involves drawing conclusions about the population from a smaller sample.

Question 15

The process of analyzing sample data to draw conclusions about the characteristics of a population is called _____.

Accepted Answer

Statistical inference involves using sample data to make inferences about a larger population, which is the process described in the question. Descriptive statistics involve summarizing and describing characteristics of the sample data itself, rather than making inferences about a larger population. Data analysis and data summarization are more general terms that can refer to any process of working with data.

Question 16

_____ analytics consists of analytical techniques that use models constructed from past data to predict the future or to assess the impact of one variable on another.

Accepted Answer

Predictive analytics involves using modeling techniques to forecast future outcomes based on historical data. It helps organizations identify patterns and trends in their data to make informed decisions and actionable insights.

Question 17

A portion of the population selected to represent the population is called _____.

Accepted Answer

A sample is a portion of the population selected to represent the population in statistics. A census, on the other hand, is a complete count of a population, while descriptive statistics refers to methods of summarizing and describing data. Statistical inference involves drawing conclusions about the population based on the sample data.

Question 18

In a post office, the mailboxes are numbered from 1 to 5,000.These numbers represent _____.

Accepted Answer

The answer of In a post office, the mailboxes are...

Question 19

Exhibit 1-2
In a sample of 3,200 registered voters, 1,440, or 45%, approve of the way the president is doing his job.
-Refer to Exhibit 1-2.The 45% approval is an example of _____.

Accepted Answer

The 45% approval rate is an example of descriptive statistics, which summarizes and describes a sample or population. It does not involve using the sample to make inferences about the population (statistical inference), nor does it refer to the entire group being studied (population). The sample size of 3,200 voters does not affect the categorization of the statistic as descriptive.

Question 20

A Scanner Data User Survey of 50 companies found that the average amount spent on scanner data per category of consumer goods was $387,325 (Mercer Management Consulting, Inc., April 24, 1997).The $387,325 is an example of _____.

Accepted Answer

The amount spent on scanner data is a numerical value, making it quantitative data. Additionally, it is a descriptive statistic because it summarizes the average amount spent per category of consumer goods. Therefore, both choices B and C are correct, making choice D the best answer. Choice A is incorrect because categorical data refers to qualitative data that can be grouped into categories, such as types of consumer goods.

Quiz 1: Data and Statistics