Statistics Exam Study Guide.
Positive correlation - answerAs one variable increases, the other variable increases
Negative correlation - answerAs one variable increases, the other decreases
A point on the scatter plot represents how many values? - answer2 (X and Y)
Relationship between linear a...
Positive correlation - answer✔As one variable increases, the other variable increases
Negative correlation - answer✔As one variable increases, the other decreases
A point on the scatter plot represents how many values? - answer✔2 (X and Y)
Relationship between linear and scatter plot diagrams? - answer✔The regression line is the
best-fitting line through a scatter plot
If you see the notation (E X)(E Y) what should you do? - answer✔First sum the Xs, then sum the
Ys, then multiply the sums
If you see the notation E XY what should you do? - answer✔First multiply each X by its partner
Y, then sum the results
If there is a relationship between "amount of coffee consumed" and "nervousness", then as the
amount of coffee consumed increases, the amount of nervousness... - answer✔Changes in
some consistent, predictable manner
What does a correlation coefficient do? - answer✔It quantifies the pattern in a relationship
In an experimental design _________, whereas in a correlational design ________. -
answer✔researchers assign each person an X score and then measure the score on the Y
variable;
researchers measure scores on variables that a participant has already experienced
If we calculate a correlation coefficient and we find that there is a relationship between the two
variables, we... - answer✔cannot conclude that changes in one variable cause changes in the
other variable
Using correlation design, a researcher found a relationship between the healthiness of one's
heart and the amount of fish oil in one's diet. The researcher should conclude that... -
answer✔although a relationship exists, one cannot infer that changes in one variable are
causing changes in another variable
Professor Johnston and strong correlation between neckties and strokes; claims wearing
neckties causes strokes. What error has he made? - answer✔Professor Johnston is drawing a
causal conclusion from correlational findings
In a correlational analysis, N stands for the - answer✔total number of pairs of scores
We should do a scatterplot of the data when we compute a correlation because the scatterplot
allows us to - answer✔see the nature of the relationship between the two variables
when plotting correlational data, the appropriate graph to use is the - answer✔scatterplot!
To know whether theres a relationship btwn two variables, you draw a line around the outer
edges of a scatterplot. You can tell there is no relationship when - answer✔the scatterplot is
either circular or elliptical, with the ellipse being parallel to the X axis
The best-fitting line through a scatterplot is known as the - answer✔regression line
what type of relationship does a horizontal line parallel to the X axis represent? - answer✔No
relationship
What kind of relationship is represented by a line slanting downward from left to right? -
answer✔A negative relationship
"the self-confidence of a group of students is positively correlated with their chances of getting
through the course"- what does this statement mean? - answer✔The chances of passing the
course tend to increase as the self-confidence scores of the students increase
In general, a positive correlation means that as the values of one variable ______, there is a
tendency for the values of the other variable to _______. - answer✔Increase; increase
In a linear relationship, as the X scores increase, the Y scores change... - answer✔in only one
direction
"the bigger they are, the harder they fall" describes... - answer✔A positive linear correlation
"The more you save, the less you spend" describes... - answer✔a negative linear correlation
Prof. Miller found correlation btwn a "need for affiliation" and # of hours spent watching
television is -.69; he should conclude... - answer✔As we observe people with higher and higher
need for affiliation, we see a tendency for those people to spend less and less time watching
television
In a non-linear or curvilinear relationship, as the X scores change, the Y scores... -
answer✔Change consistently, but in more than one direction
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 Thebright. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.49. You're not tied to anything after your purchase.
