Practice+Test+4

# Practice+Test+4 - 1. ...

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Unformatted text preview: 1. 0 X1 1 2 a) b) c) d) e) f) g) h) i) j) X2 1 2 1/6 1/3 0 1/6 1/6 0 3 0 0 1/6 Find the Marginal Probabilities Find E(X1) and E(X2) Find Var(X1) and Var(X2) Find Cov Find Rho Are they independent? If not, make it so that they are. What is the domain? Var(3X1) Var(2 ­4X2) S.D of X1 and X2 2. X= 3,7,8,4,1: Y= 8,6,3,2,5 a) Find Var(X) and Var(Y) b) Find COV(XY) c) What is Rho? d) Is this a positive or a negative relationship? 3. What does the variance tell us? 4. What does the covariance tell us? 5. x mean ­50 SD ­9 y mean ­75 SD ­25 a) b) c) d) What is the mean and SD of x if A=8x? What is the mean and SD of y if A=100/y (x –y/3) what is the SD? X ­4y what is the SD? 6. What’s the correlation of a Random Variable and its self? ...
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## This note was uploaded on 12/12/2010 for the course ECON ECON 15A taught by Professor Rajendram.patel during the Fall '10 term at UC Irvine.

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