Measures of Spread: Range & IQR

Measures of Spread: Range & IQR

Measures of Spread

• Range- the difference between the greatest and the least data values

• Interquartile range (IQR)- the difference between the 3rd and 1st quartiles

VOCAB

• quartiles- values that divide a data set into 4 equal parts

• Q1 (first quartile) is the median of the lower half of the set

• Q2 (second quartile) is the median of the WHOLE set

• Q3 (third quartile) is the median of the upper half of the set

Ex: Find the median, range, and IQR for this set: 77,84,86,90,93