"Concerning Egypt, I shall extend my remarks to a great length, because there is no country that possesses so many wonders."  (Herodotus, 5th century B.C.)
Egypt represents a rich field for ancient historical and mathematical research. Among other things, the pyramids of Egypt required considerable mathematical and engineering skills, including knowledge of volume, area, estimation, right angles, and perhaps the relationship we know as the Pythagorean theorem to compute the size, shape, number, and arrangement of the stones used to build the pyramids. The Great Pyramid of Gizeh was built around 2600 B.C., some two thousand years before the historian Herodotus made the statement quoted above.

Why did Herkimer attempt to dry his wet shoes by placing them on New York newspapers? Answer: He felt that these were the Times that dry men's soles. Things Herky would like to know: If you have one for the road at a party, are you likely to get a trooper for a chaser? Can a tattoo artist be accused of having designs on a client? 
ASSIGNMENT #45 Reading: Section 7.2 (pages 398402, plus Summary, pages 403404) Exercises: Quizzes 7.1A, 7.1B, 7.2A, 7.2B (handouts in class). 
You are in Section 7.2.
Make sure you understand the notation
For instance, if X is a random variable that canassume values in the set {1,4,7} and Y is a random variableindependent of X that can assume values in the set {10,11}, then thenrandom variable X+Y is a member of the set{1+10,1+11,4+10,4+11,7+10,7+11} = {11,12,14,15,17,18}.
A common mistake is to consider the randomvariable X+Y to be a member of the set {1,4,7,10,11}. Don't make thismistake!
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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)