Terms & Vocab
What type of data measures ONE variable at a time?
Univariate data
Hours of sleep vs. test scores - which is the explanatory variable?
Hours of sleep
Both variables increase together - what direction is this?
Positive
What is a region in a Scatterplots with NO data points called?
A gap
x: 1,2,3,4,5 | y: 2,4,6,8,10 - describe the association.
Strong, positive, linear association
What type of data records TWO variables per individual?
Bivariate data
Which axis does the explanatory variable always go on?
The x-axis
As temperature rises, hot cocoa sales drop. What direction?
Negative
What are groups of points bunched closely together called?
Clusters
Points scattered all over with no clear trend - what is the strength?
Weak - or no association
What graph is used to display bivariate data on an x-y plane?
A scatterplot
Temperature (x) vs. ice cream sales (y) - what is the response variable?
Ice cream sales
Data roughly follows a straight line - what is the form?
Linear
One point is way out in the corner, far from the rest. What is that point called?
An outlier
A scatterplot looks like a U-shape. What would you say about the form?
Not linear - it would be an exponential or logarithmic form.
What do you call a point that falls far outside the overall pattern?
An outlier
Practice hours (x) vs. free throw % (y) - which axis shows free throw %?
The y-axis
Describe a strong, positive, linear association in one sentence.
Points cluster tightly along a straight line that rises from left to right.
Two Separate groups show up - one for elementary, one for school students. What feature?
Clusters - two distinct clusters
Car age (x) vs. value (y): points go from top-left to bottom-right. Direction?
Negative direction
True or False: A scatterplot proves a cause and effect relationship.
FALSE - it shows association, not causation
GPA explains hours studied. Is the explanatory variable assigned correctly?
No - hours studied could likely explains GPA but hours studied should be explanatory.
What are the three thing you must always describe about a Scatterplots?
Direction, Form, Strength
Name all three unusual features you look for in a Scatterplots?
Outliers, Gaps, and Clusters
Study time (x) vs. quiz scores (y): tight upward line. Describe using all three terms.
Strong, positive, linear association