"Numbers are intellectual witnesses that belong only to mankind."  (Honore de Balzac, 17991850)
World loses ten days: In 1582, scientific thinkers concluded that the Julian calendar (established by Roman ruler Julius Caesar in 46 B.C.) was ten days out of line with the seasons. So Pope Gregory XIII, using advice and assistance from German mathematician Christoph Clavius (15371612) ordered a new calendar (the Gregorian calendar) put into effect. When people went to bed on October 5, 1582, they woke up the next morning on October 15, 1582. The Christian world actually lost ten calendar days.

Why did Herkimer faint when he looked at a picture of Mickey Mouse? Answer: He had a Disney spell. Herky's friends: MR. REE...this guy loved suspense stories. MYRTLE BEECH...she loved to visit seaside resorts in South Carolina. 
ASSIGNMENT #42 Reading: Section 7.2 (pages 385389) Exercises: 7.4, 7.5 (page 381), 7.17, 7.18 (page 389). 
You are in Section 7.2.
What is below is a repeat of what appeared onthe Assignment #41 page. These formula are important.
On the AP STATISTICS FORMULA SHEET (gold handoutfrom first day of class), note the formulas under the heading (II)Probability. You have here the formulas
Prob(A or B) = Prob(A)+Prob(B) Prob(A and B)
Prob(AB) = Prob(A and B)/Prob(B)
E(X) = m_{x}
= Sum(x_{i} p_{i} ) ... Note that this was used in THREE DICE GAME andROULETTE Var(X) = s_{x}^{2} = Sum
[(x_{i} m_{x} )^{2} p_{i} ] ... We haven't seen this yet, butnote that the formula involves squaring deviations from themean.
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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)