Measures of dispersion

• What does standard deviation show in a data set?

  It shows the amount of variation
• How does standard deviation assess data?

  It assesses the spread of data around the mean
• What are the steps to calculate standard deviation?

  1. Write all data in a column
  2. Calculate the mean
  3. Subtract each data number from the mean
  4. Square the result
  5. Sum the squared results and divide by (n - 1)
  6. Calculate the square root to 2 decimal places
• What is the range in a data set?

  The difference between highest and lowest values
• What is a limitation of using the range?

  It is affected by extreme values
• What does the range fail to account for?

  It doesn't show data distribution
• How does standard deviation differ from range?

  Standard deviation considers all values
• What is a potential drawback of standard deviation?

  It may hide characteristics of the data set
• What are the strengths and weaknesses of range and standard deviation?

  Strengths of range:

  • Easy to calculate

  
  

  Weaknesses of range:

  • Affected by extreme values
  • Doesn't show data distribution

  
  

  Strengths of standard deviation:

  • Precise measure of dispersion

  
  

  Weaknesses of standard deviation:

  • May hide characteristics of data