Exploring Two–Variable Data
In a scatterplot, data points lie perfectly on a downward-sloping straight line; what value would you expect for the sample correlation coefficient?
In a study examining the relationship between hours studied (X) and exam scores (Y), what significance does finding a correlation coefficient close to -1 imply about these variables?
What does a correlation coefficient of 0 indicate about two variables?
If a study finds that there is a correlation of between the number of hours studied and exam scores, which of the following best explains why we cannot conclude causation from this correlation?
What is the term for a numerical measurement describing some type of association between two variables?
When considering bivariate data where one variable is categorical and one is quantitative, which statistical method should be used to examine if there is an association between the two variables?
In an experiment designed to measure how study time correlates with test scores, if an extreme outlier is included in the data set, how might it affect Pearson's r and what should be done?
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Given that variable X has a strong positive association with Y for lower values but a weak or no association for higher values, how might this heteroscedasticity impact the calculation and interpretation of their Pearson's r?
Which symbol is commonly used to represent the sample correlation coefficient?
When the correlation coefficient is 0, it implies?