FORMAT.LATEST UPDATE
measures of variability
range, interquartile range, sum of squares, variance, standard deviation
The range and interquartile range are based on...
only 2 scores
The sum of squares, variance and standard deviation are based on...
all the scores related to one another
range
the difference between the highest value and the lowest value in a dataset
The range is calculated by...
subtracting the lowest value and the highest value in a dataset
formula for range
range= Xmax- Xmin
X=score
Is the range sensitive to outliers?
yes
interquartile range (IQR)
calculated by subtracting the lower quartile from the upper quartile
quartiles
values that divide a data set into four equal parts
formula for interquartile range
IQR= Q3-Q1
lower quartile/first quartile (Q1)
separates the lowest 1/4 of the data from the upper 3/4 of data; the median of the lower half of data
middle quartile/second quartile (Q2)
the overall median of the dataset
upper quartile/ third quartile (Q3)