16.8. Summary

Try these first

1. 1.

   Define covariance in your own words.

   Hint

   Think about how variables interact.

2. 2.

   What does a covariance of zero imply?

   Hint

   Consider what happens when variables are unrelated.

3. 3.

   What does a negative covariance indicate?

   • A direct relationship
   • An inverse relationship
   • No relationship

   Hint

   Think about how variables may move in different directions.

4. 4.

   Is correlation always between -1 and 1?

   • True
   • False

   Hint

   Consider the definitions of correlation.

5. 5.

   Given two datasets, A = {4, 5, 6} and B = {10, 20, 30}, calculate both covariance and correlation. What insights can you derive from the values?

   Hint

   Remember to calculate means first and consider the relationship between data when deriving insights.

6. 6.

   If the correlation coefficient between two variables is -0.9, what does that imply about their relationship? Can you construct a hypothetical dataset that fits this correlation?

   Hint

   Try sketching out the data points and observe how they trend together!