STAT 1000 EXAM 6 QUESTIONS AND 100%
CORRECT ANSWERS!!
What if we wish to examine relationships between 2 (or more) variables with respect to the
same population?
-We might be interested simply in the nature of the relationship between the variables
OR
-One of the variables mighg be thiguht to explain/predict the other one
What is the explanatory variable?
independent variable (x)
Explain outcome
What is the response variable?
dependent variable (y)
Outcome
What do we use to visualize/display the relationship between two quantitative variables?
A scatterplot
It displays the values of two different quantitative variable measures on the same individuals, on
a Cartesian plane
If there is no explanatory/response variable then...
The choice of axes is arbitrary
What are the 4 things we look for when examining a scatterplot?
Form
Direction
Strength
Outliers
, What is form?
What shape/form is being made from the data
Is it possible for two variables to share a non linear relationship?
Yes, variables could share a quadratic, logarithmic, exponential relationship
What is direction?
If it slopes downwards left to right it is a neg association between 2 variables
X up
Y down
If it slopes upwards left to right it is a pos association between 2 variables
X up
Y up
What is strength?
Determined by how close the points lie to a line
Closer = stronger
Scattered = weak
What are outliers in scatterplots?
- an observation may be outlying in the x, y, or both directions
-can also be an observation that simply falls outside the general pattern of points (even if it's not
extreme in either the x or y direction)
What is the numerical measure to give us a concrete description of the strength of a linear
relationship between 2 quantitative variables?
Correlation
What is the correlation coefficient?
CORRECT ANSWERS!!
What if we wish to examine relationships between 2 (or more) variables with respect to the
same population?
-We might be interested simply in the nature of the relationship between the variables
OR
-One of the variables mighg be thiguht to explain/predict the other one
What is the explanatory variable?
independent variable (x)
Explain outcome
What is the response variable?
dependent variable (y)
Outcome
What do we use to visualize/display the relationship between two quantitative variables?
A scatterplot
It displays the values of two different quantitative variable measures on the same individuals, on
a Cartesian plane
If there is no explanatory/response variable then...
The choice of axes is arbitrary
What are the 4 things we look for when examining a scatterplot?
Form
Direction
Strength
Outliers
, What is form?
What shape/form is being made from the data
Is it possible for two variables to share a non linear relationship?
Yes, variables could share a quadratic, logarithmic, exponential relationship
What is direction?
If it slopes downwards left to right it is a neg association between 2 variables
X up
Y down
If it slopes upwards left to right it is a pos association between 2 variables
X up
Y up
What is strength?
Determined by how close the points lie to a line
Closer = stronger
Scattered = weak
What are outliers in scatterplots?
- an observation may be outlying in the x, y, or both directions
-can also be an observation that simply falls outside the general pattern of points (even if it's not
extreme in either the x or y direction)
What is the numerical measure to give us a concrete description of the strength of a linear
relationship between 2 quantitative variables?
Correlation
What is the correlation coefficient?
