Question 1

The significance level of a statistical inference measures:
A)the proportion of times a conclusion about a population will be correct in the long run.
B)the proportion of times a conclusion about a population will be wrong in the long run.
C)the proportion of times an estimation procedure will be correct in the long run.
D)the proportion of times an estimation procedure will be wrong in the long run.

Accepted Answer

The significance level of a statistical inference measures the proportion of times a conclusion about a population will be wrong in the long run. This is also known as the type I error rate.

Question 2

The confidence level of a statistical inference measures:
A)the proportion of times a conclusion about a population will be correct in the long run.
B)the proportion of times a conclusion about a population will be wrong in the long run.
C)the proportion of times an estimation procedure will be correct in the long run.
D)the proportion of times an estimation procedure will be wrong in the long run.

Accepted Answer

The answer of The confidence level of a statistical inference...

Question 3

The Commissioner of Health in the state of New York wanted to study malpractice litigation in Albany last year. She randomly selected 53,000 medical records from the population of 2.5 million patients in Albany last year. The proportion of malpractice claims filed from the 53,000 patients is an example of a(n)____________________.

Accepted Answer

The answer of The Commissioner of Health in the state...

Question 4

How do confidence levels compare to significance levels?
A)Confidence levels and significance levels are both typically small.
B)Confidence levels and significance levels are both typically large.
C)Confidence levels are typically small and significance levels are typically large.
D)Confidence levels are typically large and significance levels are typically small.

Accepted Answer

Confidence levels and significance levels are both measures of uncertainty in statistical inference. However, confidence levels are used to estimate the range of plausible values for a population parameter while significance levels are used to test whether a sample statistic is unlikely to have occurred by chance alone assuming a null hypothesis. Confidence levels are typically larger than significance levels, meaning that confidence intervals tend to be wider than rejection regions. Confidence levels are expressed as a percentage (e.g. 95%) indicating the proportion of times the true population parameter would be expected to fall within the calculated interval in repeated sampling. Significance levels are often set at 5% or 1%, indicating the maximum probability of rejecting a true null hypothesis.

Question 5

The Attorney General of the state of California wanted to study criminal law in Los Angeles last year. He randomly selected 46,000 criminal records from the population of 1.5 million convicts in Los Angeles last year. From this sample, he calculated the proportion of litigations, the average amount of money involved per litigation, and the proportion of litigations resulting in a conviction. These calculations are all examples of doing ____________________ statistics.

Accepted Answer

The answer of The Attorney General of the state of...

Question 6

Briefly describe the difference between a population and a sample and give an example of each.

Accepted Answer

The answer of Briefly describe the difference between a population...

Question 7

The Human Resources Director at Illinois State University wishes to develop an employee pension package. To get an idea of what components of a pension package are most important, he selects 525 employees at random and asks them for their opinions. The group of all employees at ISU is known as the ____________________.

Accepted Answer

The answer of The Human Resources Director at Illinois State...

Question 8

Briefly describe the difference between a parameter and a statistic, and give an example of each.

Accepted Answer

The answer of Briefly describe the difference between a parameter...

Question 9

What name do we give to a descriptive measure of a sample?

Accepted Answer

The answer of What name do we give to a...

Question 10

The Human Resources Director of a large hospital wants to determine the percentage of all employees who favor a newly proposed benefits package. He selects 300 employees at random and finds that 85% approve the newly proposed package. The percentage of all employees of this company who favor the newly proposed package is a(n)____________________.

Accepted Answer

The answer of The Human Resources Director of a large...

Question 11

The Owner of a large manufacturing company wishes to develop a new employee health benefits package. He selects 500 employees at random and asks them about their preferences regarding their current health benefits package. The 500 employees selected is a(n)____________________.

Accepted Answer

The answer of The Owner of a large manufacturing company...

Question 12

Each of the following is a form of doing ____________________ statistics: 1)presenting your data using a graph; 2)calculating the mean of your sample; and 3)organizing your data into a table.

Accepted Answer

The answer of Each of the following is a form...

Question 13

The Surgeon General wanted to study malpractice litigation in Chicago. A sample of 32,000 medical records was selected from all 3.5 million patients who were discharged during the year 2011. Using the information from the sample to make conclusions about malpractice litigation in Chicago is an example of doing ____________________ statistics.

Accepted Answer

The answer of The Surgeon General wanted to study malpractice...

Question 14

The process of using sample statistics to draw conclusions about population parameters is called:
A)finding the significance level.
B)calculating descriptive statistics.
C)doing inferential statistics.
D)calculating the confidence level.

Accepted Answer

Inferential statistics is the process of using sample statistics to draw conclusions about population parameters.

Question 15

At Cedar Rapids Community College, administrators want to determine the average commuting distance for their students who commute to school. They randomly select 250 students who commute and ask them the distance of their commute to campus. From this group a mean of 19.3 miles is computed. 
 a. Describe\find the parameter. 
 b. Describe\find the statistic. 
 c. Describe the population. 
 d. Describe the sample.

Accepted Answer

The answer of At Cedar Rapids Community College, administrators want...

Question 16

Which of the following represents a population, as opposed to a sample?
A)2,000 respondents to a magazine survey which has 600,000 subscribers.
B)The first 15 students in your class completing a final exam.
C)Every fourth student to arrive at the book store on your campus.
D)All registered voters in the state of West Virginia

Accepted Answer

A population refers to a group of individuals or items that share one or more common characteristics and are the subject of statistical analysis. All registered voters in the state of West Virginia represent a population as they share the common characteristic of being registered voters in that particular state. A sample, on the other hand, is a subset of the population that is selected for statistical analysis. Choices A, B, and C all represent samples as they represent a subset of a larger population.

Question 17

A study is under way to determine the average height of all 63,000 adult walnut trees in a certain national forest. The heights of 950 randomly selected adult walnut trees are measured and analyzed. The sample in this study is:
A)the average height of the 950 randomly selected adult walnut trees.
B)the average height of all the adult walnut trees in this forest.
C)all the adult walnut trees in this forest.
D)the 950 adult walnut trees selected at random from this forest.

Accepted Answer

The sample refers to the subset of the population that is actually observed or measured for the purpose of a study. In this case, the 950 adult walnut trees selected at random from the forest constitute the sample.

Question 18

The Human Resources Director at Florida Atlantic University wishes to develop an employee benefits package. To get an idea of what components of a benefits package are most important, he selects 350 employees at random and asks them for their opinions. Numerically summarizing the preferences of these 350 employees is an example of doing ____________________ statistics.

Accepted Answer

The answer of The Human Resources Director at Florida Atlantic...

Question 19

A researcher at Florida International University (FIU)wants to estimate the average number of credits earned by students last semester at FIU. She randomly selects 750 students from last semester and finds that they averaged 13.75 credits per student. The population of interest to the researcher is:
A)all FIU students.
B)all college students.
C)all FIU students enrolled last semester.
D)the 750 FIU students selected at random.

Accepted Answer

The population of interest to the researcher is all FIU students enrolled last semester since the researcher is specifically interested in estimating the average number of credits earned by students last semester at FIU. The sample of 750 students selected at random from last semester at FIU is used to estimate the population parameter of interest. Option A includes all FIU students which may include students who did not attend last semester, making it an incorrect option. Option B includes all college students which is not relevant to the researcher's study. Option D is only the sample selected by the researcher and not the population of interest.

Question 20

A study is under way to determine the average height of all 29,000 adult pine trees in a certain national forest. The heights of 600 randomly selected adult pine trees are measured and analyzed. The parameter in the study is:
A)the average height of the 600 randomly selected adult pine trees.
B)the average height of all the adult pine trees in this forest.
C)all the adult pine trees in this forest.
D)the 600 adult pine trees selected at random from this forest.

Accepted Answer

The parameter in the study is the average height of all the adult pine trees in this forest, not just the sample of 600 that were measured. This is what the study aims to estimate.

Quiz 1: What Is Statistics

The significance level of a statistical inference measures:

The confidence level of a statistical inference measures:

How do confidence levels compare to significance levels?

Briefly describe the difference between a population and a sample and give an example of each.

Briefly describe the difference between a parameter and a statistic, and give an example of each.

What name do we give to a descriptive measure of a sample?

The Owner of a large manufacturing company wishes to develop a new employee health benefits package. He selects 500 employees at random and asks them about their preferences regarding their current health benefits package. The 500 employees selected is a(n)____________________.

Each of the following is a form of doing ____________________ statistics: 1)presenting your data using a graph; 2)calculating the mean of your sample; and 3)organizing your data into a table.

The process of using sample statistics to draw conclusions about population parameters is called:

Which of the following represents a population, as opposed to a sample?

A study is under way to determine the average height of all 63,000 adult walnut trees in a certain national forest. The heights of 950 randomly selected adult walnut trees are measured and analyzed. The sample in this study is:

A study is under way to determine the average height of all 29,000 adult pine trees in a certain national forest. The heights of 600 randomly selected adult pine trees are measured and analyzed. The parameter in the study is: