WGU C955 EXAM APPLIED PROBABILITY
AND STATISTICS EXAM STUDY GUIDE |
RATED A+ | 2024/2025 GUIDE
Population (Sampling Method)
- Correct Answer - The group you want to study
Sampling Frame (Sampling Method)
- Correct Answer - The list of people or things you pull the
sample from
Sample (Sampling Method)
- Correct Answer - The subset of the population that is being
studied
Bias in Sampling
- Correct Answer - Occurs when the sample frame does not
accurately represent the population
Simple Random Sample
- Correct Answer - Participants are randomly chosen from the
entire population
,Voluntary Sample
- Correct Answer - Researchers invite everyone from the
sampling frame to participate, those who respond are the sample.
Stratified Sample
- Correct Answer - All groups are chosen, only some people
within each group are studied
Cluster Sample
- Correct Answer - Some groups are chosen, all people in the
groups are studied
Observational Study
- Correct Answer - Someone observes what is happening in a
situation. There is no treatment, just observation
Experimental Study
- Correct Answer - Researchers apply treatment to one group
and no treatment to another control group. Causation can be
determined in a well designed, controlled experiment
Association
,- Correct Answer - Relationship between two or more variables.
A scatter plot can show the pattern of relationship between
quantitative variables. Can be established by an observational
study.
Causation
- Correct Answer - A change in one variable creates a change
in the other variable. Can be difficult to establish. Established by
an experimental study. Association or correlation does not always
causation. Lurking variables may not be included in the study, but
affect the variables that were included.
Simpson's Paradox
- Correct Answer - Occurs when a result that appears in a group
of data disappears when the groups are combined. Can only
occur when the sizes of the groups are inconsistent.
Simple Linear Equation
- Correct Answer - Models the data with a line.
, x is the explanatory variable
y is the response variable
Equation given is y = mx + b, where m is the slope and b is the y-
intercept
The sign of the slope (+ or -) matches the sign of r
Linear Interpolation
- Correct Answer - Used to predict data in simple linear
equation. It is the predictions between two known data points
Linear Extrapolation
- Correct Answer - Used to predict data in simple linear
equation. It is the predictions of the data outside of the known
data, or data larger or smaller than the max/min known data
points
Potential Problems with Simple Linear Equation
- Correct Answer - Inappropriate extrapolation: Trends do not
continue indefinitely.
Association is not causation: Watch for lurking variables.
Not representative of the sample
Small Sample Size
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller NurseMeg. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.
