8-2 Measures of Central Tendency and Range
Measure of Central Tendency A number used to describe the center of a set of data Mean, Median, Mode
Mean The sum of the data divided by the number of items in the set “average” The average teacher is Mean Ex: 1 cm, 1 cm, 5 cm, 2 cm, 2 cm, 4 cm, 2 cm, 5 cm
Mode The number that occurs most often. Mode = most often
Mode examples??? No mode One mode Two modes
Median Highway medians are in the middle. After the data set has been ordered least to greatest, it is the middle number or the mean(average) of the two middle numbers Ex: 15 yd, 7 yd, 20 yd, 17 yd, 11 yd, 20 yd
Range Is a “measure of variation” Difference between the least and greatest values
When to use what??? Mean- when data has no outliers Median- when data has outliers and there are no big gaps in the middle of the data Mode- data has many identical numbers Range- to describe the spread of data