Question 1 A study of college graduates involves three variables: income level, job satisfaction, and one-way commute times to work. List some ways the variables might be confounded. (Select all that...

Question 1

A study of college graduates involves three variables: income level, job satisfaction, and one-way commute times to work. List some ways the variables might be confounded. (Select all that apply.)

People might be very satisfied with their career as long as the income is high.

One-way commute times may be long because affordable housing is distant from the job.

People with who are very unsatisfied with their jobs will have a low income.

A working spouse could affect all three variables.

People may have a career following their passion, but have a low income or a long commute.

Question 2

a) Consider a completely randomized experiment in which a control group is given a placebo for congestion relief and a treatment group is given a new drug for congestion relief. Describe a double-blind procedure for this experiment.

1) The patients do not know which treatment the other patients received

2) Neither the patients nor those administering the treatments know which patients received which treatments.

3) Those administering the treatments do not know which patients received which treatments.

4) The patients do not know which treatment they received.

b)
What are some benefits of such a procedure? (Select all that apply.)

1)
This process should eliminate potential bias from the patients' families.

2)
This process should eliminate potential bias from patient psychology regarding benefits of the drug.

3)
This process should eliminate potential bias from the researchers.

4)
This process should eliminate potential bias from the treatment administrators

Question 3

This question has several parts that must be completed sequentially. If you skip a part of the question, you will not receive any points for the skipped part, and you will not be able to come back to the skipped part.

Tutorial Exercise

Zane is examining two studies involving how different generations classify specified items as either luxuries or necessities. In the first study, generation A is defined to be peopleages19–30.The second study defined generation A to be peopleages24–35.Zane notices that the first study was conducted in2001while the second one was conducted in2006.

(a) Are the two studies inconsistent in their description of generation A?
(b) According to the2001study, what are the birth years of generation A?

Question 4

Suppose you are looking at the 2006 results of how the Echo generation classified specified items as either luxuries or necessities. Do you expect the results to reflect how the Echo generation would classify items in 2020? Explain.

No, the generation will have aged by 14 years and their perception of items as necessities or luxuries might well have changed by then.

No, many luxury brands will no longer exist in 2020, and will thus be unavailable for purchase. Newer luxury brands will dominate the lists.

Yes, though the generation will have aged by 14 years, their perception of items as necessities or luxuries will not have changed by then.

Yes, the costs of luxuries or necessities doesn't change that much with time, so they would still be considered luxuries or necessities in 2020.

Yes, people's ideas of luxuries or necessities rarely change.

Question 5

Which technique for gathering data (observational study or experiment) do you think was used in the following studies?

(a) The Colorado Division of Wildlife netted and released 774 fish at Quincy Reservoir. There were 219 perch, 315 blue gill, 83 pike, and 157 rainbow trout.

This is an observational study because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

This is an experiment because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an observational study because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an experiment because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

(b) The Colorado Division of Wildlife caught 41 bighorn sheep on Mt. Evans and gave each one an injection to prevent heartworm. A year later, 38 of these sheep did not have heartworm, while the other three did.

This is an experiment because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an observational study because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an observational study because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.This is an experiment because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

(c) The Colorado Division of Wildlife imposed special fishing regulations on the Deckers section of the South Platte River. All trout under 15 inches had to be released. A study of trout before and after the regulation went into effect showed that the average length of a trout increased by 4.2 inches after the new regulation.

This is an experiment because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an experiment because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

This is an observational study because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.This is an observational study because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

(d) An ecology class used binoculars to watch 23 turtles at Lowell Ponds. It was found that 18 were box turtles and 5 were snapping turtles.

This is an observational study because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

This is an experiment because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an observational study because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured

.This is an experiment because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

Question 6

Which technique for gathering data (sampling, experiment, simulation, or census) do you think was used in the following studies?

(a) An analysis of a sample of 31,000 patients from New York hospitals suggests that the poor and the elderly sue for malpractice at one-fifth the rate of wealthier patients. (Journal of the American Medical Association).

samplingexperimentsimulationcensus

(b) The effects of wind shear on airplanes during both landing and takeoff were studied by using complex computer programs that mimic actual flight.

samplingexperimentsimulationcensus

(c) A study of all league football scores attained through touchdowns and field goals was conducted by the National Football League to determine whether field goals account for more scoring events than touchdowns (USA Today).

samplingexperimentsimulationcensus

(d) An Australian study included 588 men and women who already had some precancerous skin lesions. Half got skin cream containing a sunscreen with a sun protection factor of 17; half got an inactive cream. After 7 months, those using the sunscreen with the sun protection had fewer precancerous skin lesions (New England Journal of Medicine).

samplingexperimentsimulationcensus

Question 7

How would you use a completely randomized experiment in each of the following settings? Is a placebo being used or not? Be specific and give details.

(a) A veterinarian wants to test a strain of antibiotic on calves to determine their resistance to common infection. In a pasture are22 newborncalves. There is enough vaccine for10 calves.However, blood tests to determine resistance to infection can be done on all calves. (Select all that apply.)

After inoculation, test all calves to see if there is a difference in resistance to infection between the two groups.

No placebo is being used.

After inoculation, test 5 calves to see if there is a difference in resistance to infection between the two groups.

Use random selection to pick 5 calves to inoculate.

Use random selection to pick 10 calves to inoculate.

After inoculation, test 10 calves to see if there is a difference in resistance to infection between the two groups.

A placebo is used for the remaining 12 calves.

(b) The Denver Police Department wants to improve its image with teenagers. A uniformed officer is sent to a school 1 day a week for10 weeks.Each day the officer visits with students, eats lunch with students, attends pep rallies, and so on. There are18 schools,but the police department can visit only half of these schools this semester. A survey regarding how teenagers view police is sent to all18 schoolsat the end of the semester. (Select all that apply.)

After the police visits, survey all the schools to see if there is a difference in views between the two groups.

After the police visits, survey 9 of the schools to see if there is a difference in views between the two groups.

No placebo is being used.

Use random selection to pick 18 schools to visit.

A placebo is used for the remaining 9 schools.

Use random selection to pick nine schools to visit.

(c) A skin patch contains a new drug to help people quit smoking. A group of 75 cigarette smokers have volunteered as subjects to test the new skin patch. For one month, 40 of the volunteers receive skin patches with the new drug. The other volunteers receive skin patches with no drugs. At the end of the two months, each subject is surveyed regarding his or her current smoking habits. (Select all that apply.)

Use random selection to pick 35 volunteers for the skin patch with the drug.

Then record the smoking habits of the 40 volunteers to see if a difference exists between the two groups.

No placebo is being used.

Then record the smoking habits of all volunteers to see if a difference exists between the two groups.

Then record the smoking habits of the 35 volunteers to see if a difference exists between the two groups.

A placebo patch is used for the remaining 35 volunteers in the second group.

Use random selection to pick 40 volunteers for the skin patch with the drug.