AMDM Statistics Review JC

The difference between an observational study and an experimental study is...

• In an experimental study a treatment is applied

• In an observational study data is collected without changing the behavior of the participants

• Experimental studies usually compare two or more groups

• All of the above

An _________ sample is one that is representative of the population you want information about

• unadulterated

• unbiased

• biased

• interesting

The purpose of a placebo is...

• to provide the participants with a consent form

• so that the control group thinks they received treatment. This way any difference between the groups must be due to the treatment

• to reward the participants

• to place the participants in multiple groups

Why might a double blind study be used rather than just a blind study?

• two blinds are better than one

• a blind study would be limited if the blinds are closed and not opened

• sometimes the administrator of the treatment can influence the participants so a double blind study eliminates this problem

• none of the above

A _______ sampling is when you select participants because they are easily accessible

Identify the type of sampling:

An ad agency gathers information about the habits of Texas consumers who live in very small towns (less than 100 adults). They randomly select 12 of these small towns and then interview all of the adults in each of these towns.

• Simple Random

• Convenience

• Stratified

• Cluster

There are four employee classifications: doctors, medical staff (nurses, techs, etc), office staff, support staff (custodians, etc). Randomly select 10 employees from each category.

• convenience

• stratified

• cluster

• simple random

At the start of each shift, employees randomly select a number from 1 to 10, choose that person as they arrive, and then test every 10th person after that who arrives for work.

• convenience

• stratified

• systematic

• simple random

A study at JCHS showed that JCHS students take an average of 3,543 steps per day with a margin of error of ±4 % (at a 95% confidence level).

What does this margin of error mean

• The study is 95% sure that students take within 4% of the 3,543 steps per day

• That the students actually walk and average of 91 to 99 steps per day

• That the number of steps is between 3539 and 3547

• Margarine is 4% less tasty than butter

A professor at the University of Georgia wants to determine what percentage of Americans ice skate.  The last question on his final exam asks students whether or not they have gone ice skating in the past year.

Is the professor collecting categorical or quantitative data?

• quantitative

• categorical

• institutional

• olympic