First test scores for two students:

Ernie: 80, 81, 83, 79, 82 Bert: 100, 68, 82, 94, 61

Center + Variation =More than most Americans understand

From “Headlines From A Mathematically Literate World (http://mathwithbaddrawings.com/2013/12/02/headlines-from-a-mathematically-literate-world/)

Our World: Local Heat Wave Seen as Sign of Global Warming

Mathematically Literate World: Local Heat Wave Not Seen as Meaningful Indicator of Global Trends

Our World: Psychologists Tout Surprising New Findings

Mathematically Literate World: Psychologists Promise to Replicate Surprising New Findings Before Touting Them

Our World: Unemployment Rate Jumps from 7.6% to 7.8%

Mathematically Literate World: Unemployment Rate Probably a Little Under 8%; Maybe Rising, or Not, Can’t Really Tell

The takeaway about sample standard deviation “s”

•Only meaningful when paired with an average

•Average distance between average and sample data

•When s is “big” – data is highly varied (scattered)

•When s is “small” – data is highly consistent (clumped)