Study Questions

Short Answer

1. Define the standard deviation and how it differs from what the mean tells you.
Ans: The standard deviation is the average difference between the scores and the mean of a distribution. It tells us about how spread out the scores are around the mean, while the mean tells you about the representativeness of the distribution.
Learning Objective: 5-2: How are the range and standard deviation used as measures of variability?
Cognitive Domain: Comprehension
Answer Location: Standard Deviation

2. When is a range the best measure of variability?
Ans: A range is the best measure of variability when there is no extreme outlier in the distribution and when the data do not use nominal data scale.
Learning Objective: 5-3: How do the range and standard deviation compare for different distributions?
Cognitive Domain: Comprehension
Answer Location: Which Measure of Variability Should I Use?