Question 1

Determine whether the given description corresponds 
-A quality control specialist compares the output from a machine with a new lubricant to the output of machines with the old lubricant.
A) Experiment
B) Observational study

Accepted Answer

This is an experiment because the quality control specialist is intentionally manipulating the lubricant in order to observe its effect on the output of the machine.

Question 2

Determine whether the given description corresponds 
-A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest earnings per share reported for the last quarter.
A) Experiment
B) Observational study

Accepted Answer

This is an observational study because the stock analyst is simply selecting a stock based on previously reported earnings per share, without manipulating any variables or implementing any treatments.

Question 3

which of these types of sampling is used: 
-The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.
A) Random
B) Stratified
C) Cluster
D) Systematic
E) Convenience

Accepted Answer

This method is an example of random sampling, where each contestant has an equal chance of being selected.

Question 4

Determine whether the given description corresponds 
-A T.V. show's executives commissioned a study to gauge the impact of the show's ratings on the sales of its advertisers.
A) Experiment
B) Observational study

Accepted Answer

This is an observational study because the executives are collecting data on the relationship between the TV show's ratings and the sales of its advertisers without manipulating any variables. They are simply observing the natural relationship between the two variables.

Question 5

which of these types of sampling is used: 
-A sample consists of every 49th student from a group of 496 students.
A) Systematic
B) Stratified
C) Cluster
D) Random
E) Convenience

Accepted Answer

Systematic sampling involves selecting every nth item from a list or sequence, in this case, every 49th student.

Question 6

A decorator has 77 clients, 30% of whom are businesses. Find the number of business clients.
A) 25 clients
B) 75 clients
C) 54 clients
D) 23 clients

Accepted Answer

30% of 77 clients is 23.1, which rounds to 23 clients.

Question 7

The personnel manager at a company wants to investigate job satisfaction among the female employees. One evening after a meeting she talks to all 30 female employees who attended the meeting. Does this sampling plan result in a random sample? Simple random sample? Explain.

A) No; no. The sample is not random because not all female employees have the same chance of being selected. Those that didn't attend the meeting have no chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample containing female employees who did not attend the meeting.

B) Yes; yes. The sample is random because all female employees have the same chance of being selected. It is a simple random sample because all samples of size 30 have the same chance of being selected.

C) No; yes. The sample is not random because not all female employees have the same chance of being selected. Those that didn't attend the meeting have no chance of being selected. It is a simple random sample because all samples of 30 female employees have the same chance of being selected.

D) Yes; no. The sample is random because all female employees have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample containing female employees who did not attend the meeting.

Accepted Answer

The sample is not random because only those who attended the meeting had a chance of being selected, excluding those who did not attend. It is not a simple random sample because not all possible samples of female employees could be chosen, specifically those not at the meeting.

Question 8

A psychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. She randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. Does this sampling plan result in a random sample? Simple random sample? Explain.

A) No; no. The sample is not random because political science majors have a greater chance of being selected than business majors. It is not a simple random sample because some samples are not possible, such as a sample consisting of 50 business majors and 150 political science majors.

B) No; yes. The sample is not random because political science majors have a greater chance of being selected than business majors. It is a simple random sample because all samples of size 200 have the same chance of being selected.

C) Yes; no. The sample is random because all students have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample consisting of 50 business majors and 150 political science majors.

D) Yes; yes. The sample is random because all students have the same chance of being selected. It is a simple random sample because all samples of size 200 have the same chance of being selected.

Accepted Answer

The sample is not random because political science majors have a greater chance of being selected than business majors. It is not a simple random sample because some samples are not possible, such as a sample consisting of 50 business majors and 150 political science majors.

Question 9

A computer company employs 100 software engineers and 100 hardware engineers. The personnel manager randomly selects 20 of the software engineers and 20 of the hardware engineers and questions them about career opportunities within the company. Does this sampling plan result in a random sample? Simple random sample? Explain.

A) Yes; no. The sample is random because all employees have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample consisting of 30 software engineers and 10 hardware engineers.

B) No; no. The sample is not random because not all employees have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample consisting of 30 software engineers and 10 hardware engineers.

C) Yes; yes. The sample is random because all employees have the same chance of being selected. It is a simple random sample because all samples of size 40 have the same chance of being selected.

D) No; yes. The sample is not random because not all employees have the same chance of being selected. It is a simple random sample because all samples of size 40 have the same chance of being selected.

Accepted Answer

The sample is random because each engineer within their respective group (software or hardware) has an equal chance of being selected. However, it is not a simple random sample because the selection is stratified by type, meaning not all combinations of 40 engineers are possible (e.g., 30 software and 10 hardware).

Question 10

Determine which of the four levels of measurement is most appropriate.
-Nationalities of survey respondents.
A) Nominal
B) Ratio
C) Ordinal
D) Interval

Accepted Answer

Nationalities represent categories with no inherent numerical values or order, therefore, it is a nominal variable.

Question 11

A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age.
A) Convenience
B) Random
C) Stratified
D) Cluster
E) Systematic

Accepted Answer

The researcher divides the population into two age groups (strata) and selects a sample from each, which is characteristic of stratified sampling.

Question 12

On a test, 85% of the questions are answered correctly. If 51 questions are correct, how many questions are on the test?
A) 60
B) 17
C) 85
D) 167

Accepted Answer

To find the total number of questions, divide the number of correct answers by the percentage correct: 51 / 0.85 = 60.

Question 13

Determine which of the four levels of measurement  is most appropriate.
-Salaries of college professors.
A) Nominal
B) Ordinal
C) Interval
D) Ratio

Accepted Answer

Salaries of college professors are measured on a ratio scale because they have a true zero point and the differences between values are meaningful.

Question 14

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. She randomly selects ten schools from the district and interviews all of the teachers at the selected schools. Does this sampling plan result in a random sample? Simple
Random sample? Explain.

A) No; no. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is not a simple random sample because some samples are not possible, such as a sample that includes teachers from schools that were not selected.

B) Yes; no. The sample is random because all teachers have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample that includes teachers from schools that were not selected.

C) No; yes. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is a simple random sample because all samples have the same chance of being selected.

D) Yes; yes. The sample is random because all teachers have the same chance of being selected. It is a simple random sample because all samples have the same chance of being selected.

Accepted Answer

The answer of An education expert is researching teaching methods...

Question 15

Determine whether the given description corresponds to 
-A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the drug has an effect on the patients' illness.
A) Experiment
B) Observational study

Accepted Answer

This is an experiment because the clinic is actively administering a drug and a placebo to different groups to observe the effects, which involves manipulation of variables.

Question 16

which of these types of sampling is used: 
-49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348, and 481 students respectively.
A) Cluster
B) Convenience
C) Stratified
D) Random
E) Systematic

Accepted Answer

This is an example of stratified sampling, where the population is divided into subgroups (strata) such as Sophomore, Junior, and Senior classes, and samples are taken from each subgroup.

Question 17

A polling company obtains an alphabetical list of names of voters in a precinct. They select every 20th person from the list until a sample of 100 is obtained. They then call these 100 people. Does this sampling plan result in a random sample? Simple random sample? Explain.

A) Yes; no. The sample is random because all voters have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample containing the second person on the list.

B) Yes; yes. The sample is random because all voters have the same chance of being selected. It is a simple random sample because all samples of 100 voters have the same chance of being selected.

C) No; no. The sample is not random because not all voters have the same chance of being selected. The second person on the list has no chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample containing the second person on the list.

D) No; yes. The sample is not random because not all voters have the same chance of being selected. The second person on the list has no chance of being selected. It is a simple random sample because all samples of 100 voters have the same chance of being selected.

Accepted Answer

The answer of A polling company obtains an alphabetical list...

Question 18

Determine which of the four levels of measurement is most appropriate.
-Amount of fat (in grams) in cookies.
A) Interval
B) Ordinal
C) Nominal
D) Ratio

Accepted Answer

The amount of fat in grams is a ratio level of measurement because it has a true zero point and allows for the comparison of absolute magnitudes.

Question 19

which of these types of sampling is used
-A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.
A) Stratified
B) Convenience
C) Random
D) Systematic
E) Cluster

Accepted Answer

The pollster is using a computer to generate random numbers, which corresponds to random sampling, where each individual has an equal chance of being selected.

Question 20

A town obtains current employment data by polling 10,000 of its citizens this month.
A) Cross-sectional
B) Prospective
C) Retrospective
D) None of these

Accepted Answer

Cross-sectional data is collected at a single point in time, which is what is happening when the town polls its citizens for current employment data.

Quiz 1: Introduction to Statistics

Determine whether the given description corresponds -A quality control specialist compares the output from a machine with a new lubricant to the output of machines with the old lubricant.

Determine whether the given description corresponds -A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest earnings per share reported for the last quarter.

which of these types of sampling is used: -The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.

Determine whether the given description corresponds -A T.V. show's executives commissioned a study to gauge the impact of the show's ratings on the sales of its advertisers.

which of these types of sampling is used: -A sample consists of every 49th student from a group of 496 students.

A decorator has 77 clients, 30% of whom are businesses. Find the number of business clients.

The personnel manager at a company wants to investigate job satisfaction among the female employees. One evening after a meeting she talks to all 30 female employees who attended the meeting. Does this sampling plan result in a random sample? Simple random sample? Explain.

Determine which of the four levels of measurement is most appropriate. -Nationalities of survey respondents.

A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age.

On a test, 85% of the questions are answered correctly. If 51 questions are correct, how many questions are on the test?

Determine which of the four levels of measurement is most appropriate. -Salaries of college professors.

Determine whether the given description corresponds to -A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the drug has an effect on the patients' illness.

which of these types of sampling is used: -49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348, and 481 students respectively.

A polling company obtains an alphabetical list of names of voters in a precinct. They select every 20th person from the list until a sample of 100 is obtained. They then call these 100 people. Does this sampling plan result in a random sample? Simple random sample? Explain.

Determine which of the four levels of measurement is most appropriate. -Amount of fat (in grams) in cookies.

which of these types of sampling is used -A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.

A town obtains current employment data by polling 10,000 of its citizens this month.