Coffee stations in offices often rely on the honor principles for users to pay t
ID: 3159688 • Letter: C
Question
Coffee stations in offices often rely on the honor principles for users to pay their coffee, but many people cheat. Researchers at Newcastle University replaced the picture of flowers on the wall behind the coffee station with a picture of staring eyes. They found that the average contribution increased significantly when people felt they were being watched, even though the eyes were clearly not real. In this observation study of an experiment? Justify your answer A group of students in a Statistics class surveys 100 students at their university. TV sample consisted of 25 freshmen, 25 sophomores, 25 juniors, and 25 seniors. It seems unlikely they used a simple random sample. Why? What sampling procedure do you think they used? Explain your answer.Explanation / Answer
1)
In an observational study investigators observe subjects and measure variables of interest without assigning treatments to the subjects. The treatment that each subject receives is determined beyond the control of the investigator.
Experimental Studies. Unlike a descriptive study, an experiment is a study in which a treatment, procedure, or program is intentionally introduced and a result or outcome is observed.
So it is an experimental study as they introduced a program where poster of a starring eye is pasted and observing the outcome.
2)
No of freshmen = no of juniors = no of seniors = no of sophomores
b)
It looks like a stratified sampling.
Stratified sampling is a probability sampling technique wherein the researcher divides the entire population into different subgroups or strata, then randomly selects the final subjects proportionally from the different strata.