# (Solution) Math 225 Week 1: Assignment Evidence, Claims and Study types

Week 1: Assignment Evidence, Claims and Study types

Question

In a survey conducted to find out the feedback of a sports program organized in a club, the organizers asked the respondents to classify their feedback as good, fair, poor, and bad. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

The study is an observational study.

The study is an experiment. The controlled factor is the feedback.

The study is an experiment. The controlled factor is the ratings.

The study is an experiment. The controlled factor is the respondents.

Question

In the description of the following experiment, determine the experimental factor. A team of physicians testing a new liquid drug taken using an inhaler for treating colds gave the drug to one group of volunteers enrolled for the test. They gave the other group water using the same kind of inhaler.

whether or not the subject’s cold was cured

the type of liquid received by each group

the new liquid drug

all of the people in the study

Question

A researcher wants to evaluate the effect of using Facebook on happiness. Would an experimental or observational study design be more appropriate?

An experimental study should be used with the use of Facebook as the controlled factor.

An experimental study should be used with happiness as the controlled factor.

An observational study should be used because it is not possible to control the use of Facebook.

An observational study should be used because it is not possible to control happiness.

Question

In the description of the following experiment, determine the experimental factor. During a study testing a new vaccine for Zika virus, the research team grouped the volunteers enrolled for the test into Group A and Group B. Group A received an inert drug (placebo) while Group B received the vaccine.

whether or not a person contracts the Zika virus

the effectiveness of the new vaccine

the drug received by each group

the group receiving the new vaccine

Question

A study was performed with a random sample of 513 bolts produced at one factory. What population would be appropriate for generalizing conclusions from the study, assuming the data collection methods used did not introduce biases?

The conclusions would apply to all bolts produced by that factory.

The conclusions would apply to all bolts produced by any factory run by the same company.

The conclusions would apply to all bolts of the same type produced by any manufacturer.

The conclusions apply only to the bolts in the sample.

Question

A researcher is interested in the effects of watching videos just before bed on the quality of sleep. He has decided to test the claim “Watching 1 hour of video just before going to bed reduces the number of minutes of REM sleep by more than 10%. ” Which of the following data collection processes would be appropriate? Select only one answer choice.

Choose a random sample of people and ask them how many hours of video they watched last night and how much REM sleep they had.

Choose a random sample of people. Randomly select half of them and have them watch one hour of video just before going to bed, and then monitor their sleep. Have the other half not watch any video and monitor their sleep.

Choose a random sample of people. On multiple randomly selected nights, randomly assign each person to either watch one hour of video or not watch video and monitor their sleep.

Choose a random sample of people. On multiple randomly selected nights, measure the amount of video they watch and monitor their sleep.

Question

In a study to add a new feature to a software program, the programmer introduced two categories, men and women, in the survey she conducted. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

The study is an experiment. The controlled factor is the feature to be added in the software.

The study is an experiment. The controlled factor is the category, men or women.

The study is an observational study.

The study is an experiment. The controlled factor is the survey.

Question

A farmer divided his land into 2 groups of sections randomly. There is no difference in the quality of the soil between the 2 groups of land. He used Type A seeds in the first group and Type B seeds in the second group. After 3 months, the heights of the crops are measured across the two groups of land sections. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

The study is an observational study.

The study is an experiment. The controlled factor is the seed type.

The study is an experiment. The controlled factor is the land.

The study is an experiment. The controlled factor is the growth of the crops.

Question

A consumer research company is interested in determining if a certain company’s new refrigerator model is more efficient than the older model. Researchers decide to investigate the claim that the new model uses 10% less electricity than the older model for the same cooling load. To collect data, the company obtains 20 random refrigerators for each model. They are all placed in one building well separated from each other and are loaded with 50 bottles of water. The electricity usage is monitored for one month. How can the results be generalized?

The conclusions should be applicable to any unit of the new model as compared to any unit of the old model.

The conclusions should be applicable to all refrigerators made by the same manufacturer.

The conclusions only apply to the sample that was obtained for the new models as compared to the sample that was obtained for the old model.

The conclusions should be valid for new model refrigerators from any manufacturer.

Question

A study was performed with a random sample of 5 people from a certain city. What population would be appropriate for generalizing conclusions from the study, assuming the data collection methods used did not introduce biases?

The conclusions should be restricted to only the city that was sampled.

The conclusions are generalizable to all people on Earth.

The conclusions are generalizable to all people in the country.

The conclusions apply only to the sample.

The conclusions apply to people in any city.

Question

A researcher is interested in the effects of watching videos just before bed on the quality of sleep. Which of the following claims would be appropriate for this situation? Select only one answer choice.

Watching videos just before bed reduces quality of sleep.

More than 60% of people watch videos just before going to bed.

Watching 1 hour of video just before going to bed reduces the number of minutes of REM sleep by more than 10%.

Watching 1 hour of video just before going to bed reduces the quality of sleep.

Question

In a study to support drug discovery for patients with lung cancer, patients were divided into 3 groups based on the severity of the disease. Smoking and alcohol consumption habits were recorded for all 3 groups. Is this an example of an observational study or experimental study?

The study is an experiment. The controlled factor is the smoking and alcohol consumption habits.

The study is an experiment. The controlled factor is the severity of the disease.

The study is an observational study.

The study is an experiment. The controlled factor is whether or not the person has lung cancer.

Question

A study is planned to research the effects of drinking coffee on hours of sleep. Would an experimental or observational study design be more appropriate?

An observational study should be used because it is not possible to control whether or not a person drinks coffee.

An observational study should be used because it is not possible to control the number of hours of sleep a person has.

An experimental study should be used where the consumption of coffee is the experimental factor.

An experimental study should be used where the number of hours of sleep is the experimental factor.

Question

In the description of the following experiment, determine the experimental factor. A research team is testing a paste form of a drug to alleviate inflammation. Participants are grouped into Team A and Team B. Team A receives the paste form of the drug. Team B receives a similar paste with no active ingredients.

Team A and Team B

the paste with the active ingredient

whether or not the paste helps the inflammation

Question

In the description of the following experiment, determine the experimental factor. A pharmaceutical company conducted an experiment to test a breakfast drink for school children. The company enrolled students for the experiment in the age group of 6 to 10 and divided them into two groups. One group received the new breakfast drink with their normal breakfast, and the other group drank the same amount of a similar looking juice. Identify the experimental factor.

the amount of drink given to each group

the students in the two groups

the students who received the new breakfast drink

the type of drink given to each group

Solution:

Question

In a survey conducted to find out the feedback of a sports program organized in a club, the organizers asked the respondents to classify their feedback as good, fair, poor, and bad. Is the study observational or experimental? If it is an experiment, what is the controlled factor?

The study is an observational study.

The study is an experiment. The controlled factor is the feedback.

The study is an experiment. The controlled factor is the ratings.

The study is an experiment. The controlled factor is the respondents.

Question

In the description of the following experiment, determine the experimental factor. A team of physicians testing a new liquid drug taken using an inhaler for treating colds gave the drug to one group of volunteers enrolled for the test. They gave the other group water using the same kind of inhaler.

whether or not the subject’s cold was cured

the type of liquid received by each group

the new liquid drug

all of the people in the study

Question

A researcher wants to evaluate the effect of using Facebook on happiness. Would an experimental or observational study design be more appropriate?