Chapter 1 Quiz

Determine whether each variable is​ qualitative, continuous, or discrete. Screen type is a _________ variable.

Qualitative

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. Is the variable qualitative or​ quantitative? Qualitative Quantitative

Quantitative

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. What is the level of measurement for the​ variable? Interval Nominal Ordinal Ratio

Ratio

The human resource department at a certain company wants to conduct a survey regarding worker benefits. The department has an alphabetical list of all 2496 employees at the company and wants to conduct a systematic sample of size 30. Determine the individuals who will be administered the survey. Randomly select a number from 1 to k. Suppose that we randomly select 16. Starting with the first individual​ selected, the individuals in the survey will be ________.

16, 99, 182, 2423

The human resource department at a certain company wants to conduct a survey regarding worker benefits. The department has an alphabetical list of all 2496 employees at the company and wants to conduct a systematic sample of size 30. What is k​?

83

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. What is the population of interest for this portion of the​ survey? All gamers of the world All gamers of the country This is the correct answer. The time of gaming All people in the country

All gamers of the country

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. What is the response variable in the​ study? Daily consumption of salt ​ Body's ability to process salt Blood pressure Daily consumption of fruits and vegetables

Blood Pressure

A school psychologist wants to test the effectiveness of a new method of teaching Logic. She recruits 800 first​-grade students and randomly divides them into two groups. Group 1 is taught by means of the new​ method, while Group 2 is taught via traditional methods. The same teacher is assigned to teach both groups. At the end of the​ year, an achievement test is administered and the results of the two groups compared. What type of experimental design is​ this? Matched pair Completely randomized assignment Survey Observational study

Completely randomized assignment

Determine whether each variable is​ qualitative, continuous, or discrete. Number of channels available is a ______ variable.

Discrete

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. If a factor cannot be​ controlled, what should be done to reduce variability in the response​ variable? Experimental units should not be randomized to each treatment group. It is necessary to use another experimental design. Experimental units should be randomized to each treatment group.

Experimental units should be randomized to each treatment group.

Explain the difference between a single-blind and a double-blind experiment In a​ single-blind experiment, there is a control group. In a​ double-blind experiment, there is both a control group and a placebo treatment is used. A single blind experiment is one in which each experimental unit is randomly assigned to a treatment. A​ double-blind experiment is one in which similar experimental units are grouped together and the experimental units within each block are randomly assigned to treatments. In a​ single-blind experiment, the researcher does not know what the response variable is. In a​ double-blind experiment, neither the subject nor the researcher knows what the response variable is. In a​ single-blind experiment, the subject does not know which treatment is received. In a​ double-blind experiment, neither the subject nor the researcher in contact with the subject knows which treatment is received

In a​ single-blind experiment, the subject does not know which treatment is received. In a​ double-blind experiment, neither the subject nor the researcher in contact with the subject knows which treatment is received

Determine the level of measurement of the variable below: Year of birth of college students Nominal Ordinal Ratio Interval

Interval

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Gender _________.

Is not a factor

A school psychologist wants to test the effectiveness of a new method of teaching Logic. She recruits 800 first​-grade students and randomly divides them into two groups. Group 1 is taught by means of the new​ method, while Group 2 is taught via traditional methods. The same teacher is assigned to teach both groups. At the end of the​ year, an achievement test is administered and the results of the two groups compared. Which of the following explanatory variables is​ manipulated? School district Method of teaching Teacher Grade level

Method of teaching

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. Is a census feasible in this​ situation? Yes No

No

Suppose you are the president of the student government. You wish to conduct a survey to determine the student​ body's opinion regarding student services. The administration provides you with a list of the names and phone numbers of the 616 registered students. Number the names from 1 to 616 and use a random number table to produce 5 different​ three-digit numbers corresponding to the names selected. Ask the students to come to a meeting and pick five from those who come to the meeting. List the names in alphabetical order and take the first five names on the list. List each name on a separate piece of​ paper; place them all in a​ hat, and pick five. Your answer is correct.

Number the names from 1 to 616 and use a random number table to produce 5 different​ three-digit numbers corresponding to the names selected. List each name on a separate piece of​ paper; place them all in a​ hat, and pick five. Your answer is correct.

The data on the right relate to characteristics of​ high-definition televisions A through E. Identify the​ individuals, variables, and data corresponding to the variables. Determine whether each variable is​ qualitative, continuous, or discrete. Setup: A B C D E Size: 48, 45, 53, 56, 56 Screen Type: Plasma, Plasma, Projection, Plasma, Plasma Number of channels: 299, 117, 425, 269, 289 What are the variables and their corresponding data being​ studied? Size ​(48​, 45​, 53​, 56​, 56​) and number of channels available ​(299​, 117​, 425​, 269​, 289​) Setup ​(A, B,​ C, D,​ E), size ​(48​, 45​, 53​, 56​, 56​), screen type ​(Plasma​, Plasma comma Projection​, Plasma​, Plasma​), and number of channels available ​(299​, 117​, 425​, 269​, 289​) Size ​(48​, 45​, 53​, 56​, 56​), screen type ​(Plasma​, Plasma​, Projection​, Plasma comma Plasma​), and number of channels available ​(299​, 117​, 425​, 269​, 289​)

Size ​(48​, 45​, 53​, 56​, 56​), screen type ​(Plasma​, Plasma​, Projection​, Plasma comma Plasma​), and number of channels available ​(299​, 117​, 425​, 269​, 289​)

Define Statistics

Statistics is the science of​ collecting, organizing,​ summarizing, and analyzing information to draw a conclusion and answer questions. In​ addition, statistics is about providing a measure of confidence in any conclusions.

Researchers wanted to determine if there was an association between daily coffee consumption and the occurrence of skin cancer. The researchers looked at 93 comma 359 women and asked them to report their​ coffee-drinking habits. The researchers also determined which of the women had nonmelanoma skin cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of caffeinated coffee per day was associated with a reduction in nonmelanoma skin cancer. What is the explanatory​ variable? The explanatory variable is consumption of caffeinated coffee. The explanatory variable is whether the woman has nonmelanoma skin cancer or not. The explanatory variable is the number of individuals that participate in the study.

The explanatory variable is consumption of caffeinated coffee.

Researchers wanted to determine if there was an association between daily coffee consumption and the occurrence of skin cancer. The researchers looked at 93 comma 359 women and asked them to report their​ coffee-drinking habits. The researchers also determined which of the women had nonmelanoma skin cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of caffeinated coffee per day was associated with a reduction in nonmelanoma skin cancer. What is the response variable in the​ study? The response variable is whether the woman has nonmelanoma skin cancer or not. The response variable is consumption of caffeinated coffee. The response variable is the number of individuals that participate in the study.

The response variable is whether the woman has nonmelanoma skin cancer or not.

One group is treated with an experimental drug. The other is not. After one month​, both groups are questioned about their energy level. Is the study an observational study or an​ experiment? The study is an experiment because the researchers control one variable to determine the effect on the response variable. The study is an observational study because the study examines individuals in a sample comma but does not try to influence the response variable. The study is an experiment because the study examines individuals in a​ sample, but does not try to influence the variable of interest. The study is an observational study because the researchers control one variable to determine the effect on the response variable.

The study is an experiment because the researchers control one variable to determine the effect on the response variable.

Determine whether the quantitative variable is discrete or continuous: Number of batters hit by a ball in a baseball game The variable is discrete because it is not countable The variable is discrete because it is countable The variable is continuous because it is not countable The variable is continuous because it is countable

The variable is discrete because it is countable

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. Is a sample feasible in this​ situation? Yes No

Yes

A school psychologist wants to test the effectiveness of a new method of teaching Logic. She recruits 800 first​-grade students and randomly divides them into two groups. Group 1 is taught by means of the new​ method, while Group 2 is taught via traditional methods. The same teacher is assigned to teach both groups. At the end of the​ year, an achievement test is administered and the results of the two groups compared. How many levels of the treatment are​ there?

2

Suppose you are the president of the student government. You wish to conduct a survey to determine the student​ body's opinion regarding student services. The administration provides you with a list of the names and phone numbers of the 616 registered students. Obtain this sample using the portion of the random number table provided in the problem statement. Start with the first column of the first row and work down each column. Number the names from 1 to 616 and use a random number table to produce 5 different​ three-digit numbers corresponding to the names selected.

349, 465, 103, 257, 194

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. Name three factors that have been identified. Select all that apply. Age Gender Body's ability to process salt Blood pressure Daily consumption of salt Daily consumption of fruits and vegetables

Body's ability to process salt Daily consumption of salt Daily consumption of fruits and vegetables

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Daily consumption of fruits and vegetables ________.

Can be controlled

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Daily consumption of salt _______.

Can be controlled

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Body's ability to process salt ________.

Cannot be controlled

Determine whether each variable is​ qualitative, continuous, or discrete. Size is a ______ variable.

Continuous

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Age _______.

Is not a factor

Researchers wish to know if there is a link between hypertension​ (high blood​ pressure) and consumption of salt. Past studies have indicated that the consumption of fruits and vegetables offsets the negative impact of salt consumption. It is also known that there is quite a bit of​ person-to-person variability as far as the ability of the body to process and eliminate salt. ​However, no method exists for identifying individuals who have a higher ability to process salt. It is recommended that daily intake of salt should not exceed 2500 milligrams​ (mg). The researchers want to keep the design​ simple, so they choose to conduct their study using a completely randomized design. For each factor​ identified, determine whether the variable can be controlled or cannot be controlled. Blood pressure _______.

Is not a factor

A polling organization contacts 2735 undergraduates who attend a university and live in the United States and asks whether or not they had spent more than $ 200 on food in the last month. What is the sample in the​ study? The 2735 undergraduates who attend a university and live in the United States. Undergraduates who attend a university. Undergraduates who attend a university and live in the United States. The 2735 undergraduates who attend a university and have spent more than $ 200 on food.

The 2735 undergraduates who attend a university and live in the United States.

A school psychologist wants to test the effectiveness of a new method of teaching Logic. She recruits 800 first​-grade students and randomly divides them into two groups. Group 1 is taught by means of the new​ method, while Group 2 is taught via traditional methods. The same teacher is assigned to teach both groups. At the end of the​ year, an achievement test is administered and the results of the two groups compared. Identify the subjects. The 800 students All students in the school district The school district The teachers

The 800 students

Researchers wanted to determine if there was an association between daily coffee consumption and the occurrence of skin cancer. The researchers looked at 93 comma 359 women and asked them to report their​ coffee-drinking habits. The researchers also determined which of the women had nonmelanoma skin cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of caffeinated coffee per day was associated with a reduction in nonmelanoma skin cancer. In their​ report, the researchers stated that​ "After adjusting for various demographic and lifestyle​ variables, daily consumption of six or more cups was associated with a​ 30% reduced prevalence of nonmelanoma skin​ cancer." Why was it important to adjust for these​ variables? It is not important to adjust for explanatory variables. The researchers were sure that various demographic and lifestyle variables had greater influence than daily consumption of six or more cups. The researchers may be concerned with confounding that occurs when the effects of two or more explanatory variables are not separated or when there are some explanatory variables that were not considered in a​ study, but that affect the value of the response variable.

The researchers may be concerned with confounding that occurs when the effects of two or more explanatory variables are not separated or when there are some explanatory variables that were not considered in a​ study, but that affect the value of the response variable.

A school psychologist wants to test the effectiveness of a new method of teaching Logic. She recruits 800 first​-grade students and randomly divides them into two groups. Group 1 is taught by means of the new​ method, while Group 2 is taught via traditional methods. The same teacher is assigned to teach both groups. At the end of the​ year, an achievement test is administered and the results of the two groups compared. What is the response variable in this​ experiment? The​ students' ability in Logic The score of Group 2 on the achievement test The score of Group 1 on the achievement test The score on the achievement test

The score on the achievement test

The data on the right relate to characteristics of​ high-definition televisions A through E. Identify the​ individuals, variables, and data corresponding to the variables. Determine whether each variable is​ qualitative, continuous, or discrete. Setup: A B C D E Size: 48, 45, 53, 56, 56 Screen Type: Plasma, Plasma, Projection, Plasma, Plasma Number of channels: 299, 117, 425, 269, 289 What are the individuals being​ studied? Televisions with screen sizes between 40 in and 60 in. Television setups that include more than 100 channels. Plasma and projection widescreen​ high-definition televisions. The​ high-definition television setups A through E.

The​ high-definition television setups A through E.

Researchers wanted to determine if there was an association between daily coffee consumption and the occurrence of skin cancer. The researchers looked at 93 comma 359 women and asked them to report their​ coffee-drinking habits. The researchers also determined which of the women had nonmelanoma skin cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of caffeinated coffee per day was associated with a reduction in nonmelanoma skin cancer. What type of observational study was​ this? Explain. This was a​ cross-sectional study because all information about the individuals was collected at a specific point in time. This was a​ case-control study because individuals that had a certain characteristic were matched with those that did not. This was a cohort study because it identified a group of individuals to participate in the study and observed the group over a period of time.

This was a​ cross-sectional study because all information about the individuals was collected at a specific point in time.

Consider a survey conducted of computer gamers in a certain country. One aspect of the survey is to determine the the time of gaming per day in a particular country. What is the variable of interest for this portion of the​ survey? Number of all people in the country Time of gaming per day Your answer is correct. Gamers All gamers of the country

Time of gaming per day

A polling organization contacts 2735 undergraduates who attend a university and live in the United States and asks whether or not they had spent more than $ 200 on food in the last month. What is the population in the​ study? Undergraduates who attend a university and live in the United States and have spent more than $ 200 on food. Undergraduates who attend a university and live in the United States. Undergraduates who attend a university and have spent more than $ 200 on food. Undergraduates who attend a university.

Undergraduates who attend a university and live in the United States.