# (Answered) MATH399N Week 1 Assignment: Statistical Study Design

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?

# Question

A biology student is interested in the relationship between temperature and germination time for soy beans. The student gets sample seeds from multiple sources and randomly selects 180 seeds from them. Then he sets up three growing stations, one at 20∘C, one at 15∘C, and one at 25∘C. He divides the seeds into three groups of 60 and plants the seeds from each group in a growing station. He records the germination time for each seed.

Is this an observational study or an experiment? If it is an experiment, what is the controlled factor?

# Question

A study was conducted among school students on the relationship between getting up late and getting to school late. Is this an example of an observational study or experimental study? If it is an experiment, what is the controlled factor?

# 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?

# Question

A candy manufacturer is interested in the distribution of colors in each of its packages of candy sold. The manufacturer randomly sample packages from multiple batches at one factory. Are the results generalizable to the company’s other factories that produce the same candy?

# 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%.” How should the number of hours of video be treated?

# Question

A study was performed with a random sample of 200 people from one college. What population would be appropriate for generalizing conclusions from the study, assuming the data collection methods used did not introduce biases?

# Question

A consumer research company is interested in determining if a certain company’s new refrigerator model is more efficient than the older model. What should the researchers do first?

# 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?

# Question

A candy manufacturer is interested in the distribution of colors in each of its packages of candy sold. What should the researchers do first?

# 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.

# Question

A study was performed with a random sample of 200 people from one college. What population would be appropriate for generalizing conclusions from the study, assuming the data collection methods used did not introduce biases?.

# Question

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

# Question

A scientist is interested in finding out the effect of soil quality on crop quality. Would an experimental or observational study design be more appropriate?.

# Solution:

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?

Correct answer: The study is an observational study.

### Question

A biology student is interested in the relationship between temperature and germination time for soy beans. The student gets sample seeds from multiple sources and randomly selects 180 seeds from them. Then he sets up three growing stations, one at 20∘C, one at 15∘C, and one at 25∘C. He divides the seeds into three groups of 60 and plants the seeds from each group in a growing station. He records the germination time for each seed.

Is this an observational study or an experiment? If it is an experiment, what is the controlled factor

correct answer: The study is an experiment. The controlled factor is the temperature.….Click link below to purchase full tutorial at \$5