Before calculating a correlation coefficient, explain why you
would create and examine a scatterplot of the relationship. In your
response, please discuss (a) linearity (b) homoscedasticity, (c)
restriction of range, and (d) the presence of outliers.
Use a scatterplot and the linear correlation coefficient r to
determine whether there is a correlation between the two variables.
Use alphaequals0.05. x 6 1 4 8 5 y 5 0 2 7 4 Click here to view a
table of critical values for the correlation coefficient.
LOADING... Does the given scatterplot suggest that there is a
linear correlation? A. Yes comma because the points appear to have
a straight line pattern. B. Yes, because the data does not follow...
Correlational Research
A)Strength of correlation: correlation coefficient Explain what
it is. Use an example.
The statistic has a value from 0 to 1: 0 = no relationship
between 2 variables > .3, a significant relationship > .5, a
strong relationship
b)Weakness of correlational research Explain how correlational
research only describes relationships between variables. It can’t
be used to test for cause and effect. Correlation doesn’t imply
causation, only co-occurrence.
Use a scatterplot and the linear correlation coefficient r r to
determine whether there is a correlation between the two variables.
(Note: Use software, and don't forget to look at the scatterplot!)
x 0.6 1.1 2.3 3.1 4.7 5.9 6.5 7.3 8.9 9.2 10.9 11.9 12.8 13.6 14.6
y 15.5 13.9 10.9 13.4 10.8 11.1 10.4 5.7 4.3 3.8 6 4.5 4.2 -0.4 0.1
(a) r= r= equation editor Equation Editor (b) There is A. a
positive correlation between x...
Why is it advisable to generate a scatterplot before computing a
correlation coefficient between two variables? Describe how a
scatterplot might differ when viewing correlations that represent
positive, negative, and no relationship between predictor and
criterion variables. Is it possible to have a relation between
variables that systematic (i.e., reliable and predictable) yet not
linear?
Construct a scatterplot, find the value of the linear
correlation coefficient r, find the critical value of r from Table
A-6 by using a 0.05, and determine whether there is a linear
correlation between the two variables.
Song Audiences and Sales The table below lists
the numbers of audience impressions (in hundreds of millions)
listening to songs and the corresponding numbers of albums sold (in
hundreds of thousands). The number of audience impressions is a
count of the number of...
Why is it advisable to generate a scatterplot before computing a
correlation coefficient between two variables? Describe how a
scatterplot might differ when viewing correlations that represent
positive, negative, and no relationship between predictor and
criterion variables. Is it possible to have a relation between
variables that systematic (i.e., reliable and predictable) yet not
linear?
What are the factors that affect the magnitude of correlation
coefficient? (a) List at least 2 factors and (b) explain how they
affect the magnitude of correlation coefficient.
Identify the strength ("weak" "moderate" "strong") and direction
("positive" "negative") of the correlation coefficients.
Coefficient
Strength
Direction
+.09
–.87
+.59