Flashcards in Chapter 4- Exploring Data: Variability Deck (12):
Highest score minus the lowest
Want range to be variable?
If the range is not very variable, it means the data hasn't changed that much. You can say with certainty. If the gap is huge it's variable. If it's not it is invariable.
What should you use to measure variability??
Measure of the dispersion of scores around the mean
Lower case sigma
S with a hat. Estimate of populations far is variability
Raw scores minus the mean of the distribution, whether the distribution is a sample or pop.
If raw is greater- positive deviation scores
If raw is lower- neg. Ds
Equal to- deviation score of zero
X - X bar
Data point minus the mean
How much it deviates