Reading Scatter Plots and Understanding Correlations.
Due Sunday 9/22/13 by 11:59pm
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Click on graphs to enlarge.
|Correlation Coefficient -0.07|
What can we see from the above scatter plot of hair length vs. height? Is there a correlation? How strong is it? If so, is it positive or negative; strong or weak? What information about the students in our class does this graph give you? Are there a few "outliers" or extreme data points that seem unusual? If you throw them out of the data set what does the correlation look like? What other information would be helpful to interpret the data?
|Correlation Coefficient +0.47|
Above is the data we collected about our shoe sizes vs our heights. Can you see a relationship? Is there a correlation? If so, is it positive or negative? How strong is it? Does shoe size cause height to change? Does height cause shoe size to change?
|Correlation Coefficient -0.34|
Finally, the above graph shows the relationship between shoe size and hair length. Is there a correlation? If so, is it positive or negative? How strong is it? What third variable which is not shown on the graphs might be causing the relationship between shoe size and hair length? Does correlation imply causation? Why or why not?