10x.4. Properties

Try these first

1. 1.

   What is the non-negativity property of variance?

   Hint

   What happens when you square a number?

2. 2.

   Explain the impact of an outlier on standard deviation.

   Hint

   What does an extreme value in the dataset do?

3. 3.

   What is the minimum value of variance?

   • -1
   • 0
   • 1

   Hint

   Think about squaring numbers.

4. 4.

   True or False: Standard deviation can be negative.

   • True
   • False

   Hint

   What does that square root do?

5. 5.

   Given the data set {5, 6, 8, 10, 15}, calculate the variance. Discuss the role a high value (15) plays in your computation.

   Hint

   Make sure to calculate the squared differences.

6. 6.

   You have two morphological measurements of a model, both with variances of 25. If you scale one by a factor of -4, what is the new variance, and what does it signify?

   Hint

   Remember how to apply the scaling rule to variance.