Reading Quiz CH8 Flashcards
The numerical coefficient that is used to indicate the the extent to which two variables are related, or associated, is called which of the following?
Pearson’s product moment correlation coefficient
A perfect positive correlation would result in a coefficient equal to _________ whereas a perfect negative correlation would result in a coefficient equal to ______.
+1.00 and -1.00, respectively
True or False: Cause and effect may be present in a relationship between two variables; however, correlation does not prove causation.
True
When attempting to visually assess the degree to which two variables might be related to one another, producing which of the following plots would be most appropriate?
Scatter Plot
Which of the following are true in regard to the best fit line?
a. It represents the best linear estimate of the relationship between two variables, b. Generally speaking, the best fit line for a positive relationship will slope upwards (from left to right), whereas the best fit line for a negative relationship will slope downwards (from left to right) c. If the relationship between two variables was zero (r = 0.00), the slope of the best fit line would also be zero (meaning that the line would be perfectly horizontal or vertical); All of the above are true
If we ran a correlation analysis and found that two variables were correlated at r = .64, how much common variance could we say is “shared” between these two variables?
41%
If we ran a correlation analysis and found that 82% of the variance in variable Y could be explained by (or is shared with) the variance in variable X, what percentage of the variance in variable Y must be left unexplained? (Enter as a percentage; e.g. 10%)
18%
What determines whether or not our data have violated the assumption of homoscedasticity?
If we plotted our residuals and found that the variance of the residuals does vary (not constant), we would determine that we have violated the assumption of homoscedasticity.
