"I was gratified to .be able to answer promptly. I said I don't know."  (Mark Twain)
The Pythagoreans (cult whose leader was Pythagoras, founded around 500 B.C.) were number mystics, not scientific sages. Long after the death of Pythagoras, the cult split into two distinct schools. Those who continued with mysticism and rituals became the akousmatikoi (translated "those who hear") school. The other school drifted away from the mystic approach to numbers and used them for what we would call scientific purposes. This group represented the mathematikoi (translated "those interested in science") school. Do you see where our modern word mathematics comes from? 
Answer: The Wrath of Grapes. Herky 's friends: DAFFY DILL ...she's crazy about flowers. M. T. HEAD ...this guy isn't too smart. 
Reading: The SUMMARY on pages 121122.
Exercises: None

You are in Sections 3.2 and 3.3
Understand "least squares."
Note that formulas that appear on pages 129 and140 are on the formula sheet provided to those who take the APStatistics Examination.
Don't confuse slope ofleast squares regression line with thecorrelation, r.The relationship between these numbers is indicated on page140.
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Text:
The Practice of Statistics, by Yates, Moore, McCabe. New York,W.H. Freeman and Company, 1999. (ISBN 0716733706)
Supplemental books:
The Cartoon Guide to Statistics, by Gonick and Smith. NewYork, HarperCollins Publishers, 1993. (ISBN 0062731025)
How to Lie with Statistics, by Darrell Huff. New York, W.W.Norton & Company, 1982 (ISBN 039309426X)