10.x.2. Variance

Try these first

1. 1.

   What does variance measure?

   Hint

   Think about how spread out the data is.

2. 2.

   What is the standard deviation in relationship to variance?

   Hint

   Recall the formula connecting the two.

3. 3.

   Variance provides insights into:

   • Central tendency
   • Data dispersion
   • Data accuracy

   Hint

   Think about what variance tells you about data.

4. 4.

   Standard deviation is the square root of:

   • True
   • False

   Hint

   Consider how the concepts are connected.

5. 5.

   You have the following measurements of a mechanical component's diameter: 10.2, 10.4, 10.1, 10.3, 10.5. Calculate the variance and interpret what it means for quality control.

   Hint

   Find the mean first and square deviations!

6. 6.

   You are analyzing the daily rainfall (in cm) over a month: 1.0, 2.2, 0, 1.5, 3.1, 0, 2.0, 1.8, 0.5, 1.0, 2.5, 0.3. Calculate variance. What does this tell you about the variability of rainfall?

   Hint

   Remember to compute the mean rainfall first!